Programs & Examples On #Cross server

plot with custom text for x axis points

This worked for me. Each month on X axis

str_month_list = ['January','February','March','April','May','June','July','August','September','October','November','December']
ax.set_xticks(range(0,12))
ax.set_xticklabels(str_month_list)

Best way to store date/time in mongodb

One datestamp is already in the _id object, representing insert time

So if the insert time is what you need, it's already there:

Login to mongodb shell

ubuntu@ip-10-0-1-223:~$ mongo 10.0.1.223
MongoDB shell version: 2.4.9
connecting to: 10.0.1.223/test

Create your database by inserting items

> db.penguins.insert({"penguin": "skipper"})
> db.penguins.insert({"penguin": "kowalski"})
> 

Lets make that database the one we are on now

> use penguins
switched to db penguins

Get the rows back:

> db.penguins.find()
{ "_id" : ObjectId("5498da1bf83a61f58ef6c6d5"), "penguin" : "skipper" }
{ "_id" : ObjectId("5498da28f83a61f58ef6c6d6"), "penguin" : "kowalski" }

Get each row in yyyy-MM-dd HH:mm:ss format:

> db.penguins.find().forEach(function (doc){ d = doc._id.getTimestamp(); print(d.getFullYear()+"-"+(d.getMonth()+1)+"-"+d.getDate() + " " + d.getHours() + ":" + d.getMinutes() + ":" + d.getSeconds()) })
2014-12-23 3:4:41
2014-12-23 3:4:53

If that last one-liner confuses you I have a walkthrough on how that works here: https://stackoverflow.com/a/27613766/445131

HttpClient.GetAsync(...) never returns when using await/async

I was using to many await, so i was not getting response , i converted in to sync call its started working

            using (var client = new HttpClient())
            using (var request = new HttpRequestMessage())
            {
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                request.Method = HttpMethod.Get;
                request.RequestUri = new Uri(URL);
                var response = client.GetAsync(URL).Result;
                response.EnsureSuccessStatusCode();
                string responseBody = response.Content.ReadAsStringAsync().Result;
               

MySQL "CREATE TABLE IF NOT EXISTS" -> Error 1050

You can use the following query to create a table to a particular database in MySql.

create database if not exists `test`;

USE `test`;

SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;

/*Table structure for table `test` */

CREATE TABLE IF NOT EXISTS `tblsample` (

  `id` int(11) NOT NULL auto_increment,   
  `recid` int(11) NOT NULL default '0',       
  `cvfilename` varchar(250)  NOT NULL default '',     
  `cvpagenumber`  int(11) NULL,     
  `cilineno` int(11)  NULL,    
  `batchname`  varchar(100) NOT NULL default '',
  `type` varchar(20) NOT NULL default '',    
  `data` varchar(100) NOT NULL default '',
   PRIMARY KEY  (`id`)

);

Convert UTF-8 with BOM to UTF-8 with no BOM in Python

I found this question because having trouble with configparser.ConfigParser().read(fp) when opening files with UTF8 BOM header.

For those who are looking for a solution to remove the header so that ConfigPhaser could open the config file instead of reporting an error of: File contains no section headers, please open the file like the following:

configparser.ConfigParser().read(config_file_path, encoding="utf-8-sig")

This could save you tons of effort by making the remove of the BOM header of the file unnecessary.

(I know this sounds unrelated, but hopefully this could help people struggling like me.)

Change font-weight of FontAwesome icons?

2018 Update

Font Awesome 5 now features light, regular and solid variants. The icon featured in this question has the following style under the different variants:

fa-times variants

A modern answer to this question would be that different variants of the icon can be used to make the icon appear bolder or lighter. The only downside is that if you're already using solid you will have to fall back to the original answers here to make those bolder, and likewise if you're using light you'd have to do the same to make those lighter.

Font Awesome's How To Use documentation walks through how to use these variants.


Original Answer

Font Awesome makes use of the Private Use region of Unicode. For example, this .icon-remove you're using is added in using the ::before pseudo-selector, setting its content to \f00d ():

.icon-remove:before {
    content: "\f00d";
}

Font Awesome does only come with one font-weight variant, however browsers will render this as they would render any font with only one variant. If you look closely, the normal font-weight isn't as bold as the bold font-weight. Unfortunately a normal font weight isn't what you're after.

What you can do however is change its colour to something less dark and reduce its font size to make it stand out a bit less. From your image, the "tags" text appears much lighter than the icon, so I'd suggest using something like:

.tag .icon-remove {
    color:#888;
    font-size:14px;
}

Here's a JSFiddle example, and here is further proof that this is definitely a font.

Convert String array to ArrayList

Using Collections#addAll()

String[] words = {"ace","boom","crew","dog","eon"};
List<String> arrayList = new ArrayList<>(); 
Collections.addAll(arrayList, words); 

Detect Android phone via Javascript / jQuery

How about this one-liner?

var isAndroid = /(android)/i.test(navigator.userAgent);

The i modifier is used to perform case-insensitive matching.


Technique taken from Cordova AdMob test project: https://github.com/floatinghotpot/cordova-admob-pro/wiki/00.-How-To-Use-with-PhoneGap-Build

Test method is inconclusive: Test wasn't run. Error?

For me, the problem was a corrupt NUnit/ReSharper settings XML-file (due to an unexpected power shortage).

To identify the error I started Visual Studio with this command:

devenv.exe /ReSharper.LogFile C:\temp\resharper.log /ReSharper.LogLevel Verbose

Examining the file revealed the following exception:

09:45:31.894 |W| UnitTestLaunch                | System.ApplicationException: Error loading settings file
System.ApplicationException: Error loading settings file ---> System.Xml.XmlException: Root element is missing.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlLoader.Load(XmlDocument doc, XmlReader reader, Boolean preserveWhitespace)
   at System.Xml.XmlDocument.Load(XmlReader reader)
   at System.Xml.XmlDocument.Load(String filename)
   at NUnit.Engine.Internal.SettingsStore.LoadSettings()
   --- End of inner exception stack trace ---
   at NUnit.Engine.Internal.SettingsStore.LoadSettings()
   at NUnit.Engine.Services.SettingsService.StartService()
   at NUnit.Engine.Services.ServiceManager.StartServices()
   at NUnit.Engine.TestEngine.Initialize()
   at NUnit.Engine.TestEngine.GetRunner(TestPackage package)
   at JetBrains.ReSharper.UnitTestRunner.nUnit30.BuiltInNUnitRunner.<>c__DisplayClass1.<RunTests>b__0()
   at JetBrains.ReSharper.UnitTestRunner.nUnit30.BuiltInNUnitRunner.WithExtensiveErrorHandling(IRemoteTaskServer server, Action action)

Note that this is NOT the test project's app.config!

A quick googling around identified the following file as the culprit:

%LOCALAPPDATA%\NUnit\Nunit30Settings.xml

It existed, but was empty. Deleting it and restarting Visual Studio solved the problem.

(Using Visual Studio Professional 2017 v15.3.5 and ReSharper 2017.2.1).

Sorting dictionary keys in python

my_list = sorted(dict.items(), key=lambda x: x[1])

C# Return Different Types?

My post here is strictly related to Blazor v5 but should work in 3.x as well. Additionally, I'm using these methods with bootstrap 4.5 and 5.0 beta 1 but you could easily adapt it to use style's instead of classes or use your own classes.

To those recommending dynamic, I thank you. The dynamic type seems like it can be very valuable when used correctly. Most of the time you'll probably use an interface but this wasn't plausible for me. I went ahead and updated my project with a dynamic return type and it's working great while being the quickest, cleanest solution.

I previously added the following extension methods to boolean types to help me avoid long ternary operators in razor page code. Here are the 3 main extension methods I use to accomplish it:

public static T Then<T>(this bool value, T result) => value ? result : default;    
public static T Then<T>(this bool value, T thenResult, T elseResult) => value ? thenResult : elseResult;
public static T Else<T>(this bool value, T result) => !value ? result : default;

The following are examples of that implementation:

<div class="@Hidden.Then("d-none")">
    Hidden content...
</div>

Note: ErrorOrWarning would hide the content if there was no error/warning so I could default it to yellow/italic but this is an example so please use your imagination:

<div class="@ErrorOrWarning.Else("d-none")" style="@Error.Then("color:red;font-weight:bold;","color:yellow;font-style:italic;")">
    Error/Warning content...
</div>

This is the typical implementation without the extension methods. It's common to see this technique in Blazor guides/tutorials/videos online. There are cleaner ways to handle it but this is the basic idea:

<div class="@(ErrorOrWarning ? "" : "d-none")" style="@(Error ? "color:red;font-weight:bold;" : "color:yellow;font-style:italic;")">
    Error/Warning content...
</div>

While this might not seem like too big a difference, if you have a lot of dynamic content/styles driving your page, it can get really messy. With those 3 lines of code you can enhance the readability and cleanliness and it really does reduce risk of typos. Adding two more extension methods, you can reduce the risk even further Note: Again, this is using bootstrap class "d-none" for the style "display:none!important" but you could just as easily replace with your own usage:

public static string ThenShow(this bool value) => value ? "" : "d-none";
public static string ThenHide(this bool value) => value ? "d-none" : "";

The limitation I previously faced was when using the overloaded Then(thenResult, elseResult), each of the parameters must be of the same type. 99% of the time this is fine. Actually, another 0.5% of the time it's still okay because you can probably solve it quickly with a .ToString() or an explicit cast.

What I ran into, and what took me to this post was: I have a control you can imagine as a button. There is an Enum property allowing the user to select an icon to display. The selected Enum dynamically populates a readonly MarkupString property. As an alternative option, they can use the ChildContent (or IconContent in my example) of type RenderFragment. This will let them manually add anything they want (maybe an iFrame to stackoverflow haha) but my intention is for them to add style, most likely in the form of an icon.

I know I can cast/convert one to the other however my existing extension method is so clean and simple, it would be great to be able to use pass the MarkupString and RenderFragment together as parameters, conditionally output to the razor page. So, thanks to this post, I changed my Then(thenResult, elseResult) extension methods to use unique generic parameter types and return a dynamic type like so:

public static dynamic Then<T,E>(this bool value, T thenResult, E elseResult) => value ? thenResult : elseResult;

Now in my razor page I have a very simple line for the icon output. Note: IconContent is a RenderFragment and IconMarkup is a MarkupString.

@((@IconContent == null).Then(IconMarkup, IconContent))

And because I love extension methods and I'm typing this up, I took it a step further with another extension method:

public static bool IsNull(this RenderFragment value) => value == null;

Which enables the extremely clean and simple:

@IconContent.IsNull().Then(IconMarkup, IconContent)

Here's the extra extension method I mentioned above which converts a string to a MarkupString. It might be overkill but I like it.

public static MarkupString ToMarkup(this string value) => (MarkupString)value;

Let me know if you have a better recommendation or if you think I'm doing something wrong. I'm sure this post makes it seem like I overuse extension methods but I really don't. I keep their use limited to outcomes such as I've outlined in this post.

How do you convert a byte array to a hexadecimal string, and vice versa?

Here's my shot at it. I've created a pair of extension classes to extend string and byte. On the large file test, the performance is comparable to Byte Manipulation 2.

The code below for ToHexString is an optimized implementation of the lookup and shift algorithm. It is almost identical to the one by Behrooz, but it turns out using a foreach to iterate and a counter is faster than an explicitly indexing for.

It comes in 2nd place behind Byte Manipulation 2 on my machine and is very readable code. The following test results are also of interest:

ToHexStringCharArrayWithCharArrayLookup: 41,589.69 average ticks (over 1000 runs), 1.5X ToHexStringCharArrayWithStringLookup: 50,764.06 average ticks (over 1000 runs), 1.2X ToHexStringStringBuilderWithCharArrayLookup: 62,812.87 average ticks (over 1000 runs), 1.0X

Based on the above results it seems safe to conclude that:

  1. The penalties for indexing into a string to perform the lookup vs. a char array are significant in the large file test.
  2. The penalties for using a StringBuilder of known capacity vs. a char array of known size to create the string are even more significant.

Here's the code:

using System;

namespace ConversionExtensions
{
    public static class ByteArrayExtensions
    {
        private readonly static char[] digits = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };

        public static string ToHexString(this byte[] bytes)
        {
            char[] hex = new char[bytes.Length * 2];
            int index = 0;

            foreach (byte b in bytes)
            {
                hex[index++] = digits[b >> 4];
                hex[index++] = digits[b & 0x0F];
            }

            return new string(hex);
        }
    }
}


using System;
using System.IO;

namespace ConversionExtensions
{
    public static class StringExtensions
    {
        public static byte[] ToBytes(this string hexString)
        {
            if (!string.IsNullOrEmpty(hexString) && hexString.Length % 2 != 0)
            {
                throw new FormatException("Hexadecimal string must not be empty and must contain an even number of digits to be valid.");
            }

            hexString = hexString.ToUpperInvariant();
            byte[] data = new byte[hexString.Length / 2];

            for (int index = 0; index < hexString.Length; index += 2)
            {
                int highDigitValue = hexString[index] <= '9' ? hexString[index] - '0' : hexString[index] - 'A' + 10;
                int lowDigitValue = hexString[index + 1] <= '9' ? hexString[index + 1] - '0' : hexString[index + 1] - 'A' + 10;

                if (highDigitValue < 0 || lowDigitValue < 0 || highDigitValue > 15 || lowDigitValue > 15)
                {
                    throw new FormatException("An invalid digit was encountered. Valid hexadecimal digits are 0-9 and A-F.");
                }
                else
                {
                    byte value = (byte)((highDigitValue << 4) | (lowDigitValue & 0x0F));
                    data[index / 2] = value;
                }
            }

            return data;
        }
    }
}

Below are the test results that I got when I put my code in @patridge's testing project on my machine. I also added a test for converting to a byte array from hexadecimal. The test runs that exercised my code are ByteArrayToHexViaOptimizedLookupAndShift and HexToByteArrayViaByteManipulation. The HexToByteArrayViaConvertToByte was taken from XXXX. The HexToByteArrayViaSoapHexBinary is the one from @Mykroft's answer.

Intel Pentium III Xeon processor

    Cores: 4 <br/>
    Current Clock Speed: 1576 <br/>
    Max Clock Speed: 3092 <br/>

Converting array of bytes into hexadecimal string representation


ByteArrayToHexViaByteManipulation2: 39,366.64 average ticks (over 1000 runs), 22.4X

ByteArrayToHexViaOptimizedLookupAndShift: 41,588.64 average ticks (over 1000 runs), 21.2X

ByteArrayToHexViaLookup: 55,509.56 average ticks (over 1000 runs), 15.9X

ByteArrayToHexViaByteManipulation: 65,349.12 average ticks (over 1000 runs), 13.5X

ByteArrayToHexViaLookupAndShift: 86,926.87 average ticks (over 1000 runs), 10.2X

ByteArrayToHexStringViaBitConverter: 139,353.73 average ticks (over 1000 runs),6.3X

ByteArrayToHexViaSoapHexBinary: 314,598.77 average ticks (over 1000 runs), 2.8X

ByteArrayToHexStringViaStringBuilderForEachByteToString: 344,264.63 average ticks (over 1000 runs), 2.6X

ByteArrayToHexStringViaStringBuilderAggregateByteToString: 382,623.44 average ticks (over 1000 runs), 2.3X

ByteArrayToHexStringViaStringBuilderForEachAppendFormat: 818,111.95 average ticks (over 1000 runs), 1.1X

ByteArrayToHexStringViaStringConcatArrayConvertAll: 839,244.84 average ticks (over 1000 runs), 1.1X

ByteArrayToHexStringViaStringBuilderAggregateAppendFormat: 867,303.98 average ticks (over 1000 runs), 1.0X

ByteArrayToHexStringViaStringJoinArrayConvertAll: 882,710.28 average ticks (over 1000 runs), 1.0X


How to have PHP display errors? (I've added ini_set and error_reporting, but just gives 500 on errors)

Syntax errors is not checked easily in external servers, just runtime errors.

What I do? Just like you, I use

ini_set('display_errors', 'On');
error_reporting(E_ALL);

However, before run I check syntax errors in a PHP file using an online PHP syntax checker.

The best, IMHO is PHP Code Checker

I copy all the source code, paste inside the main box and click the Analyze button.

It is not the most practical method, but the 2 procedures are complementary and it solves the problem completely

How to throw RuntimeException ("cannot find symbol")

you will have to instantiate it before you throw it

throw new RuntimeException(arg0) 

PS: Intrestingly enough the Netbeans IDE should have already pointed out that compile time error

Interesting 'takes exactly 1 argument (2 given)' Python error

The call

e.extractAll("th")

for a regular method extractAll() is indeed equivalent to

Extractor.extractAll(e, "th")

These two calls are treated the same in all regards, including the error messages you get.

If you don't need to pass the instance to a method, you can use a staticmethod:

@staticmethod
def extractAll(tag):
    ...

which can be called as e.extractAll("th"). But I wonder why this is a method on a class at all if you don't need to access any instance.

Angular 2 - View not updating after model changes

Instead of dealing with zones and change detection — let AsyncPipe handle complexity. This will put observable subscription, unsubscription (to prevent memory leaks) and changes detection on Angular shoulders.

Change your class to make an observable, that will emit results of new requests:

export class RecentDetectionComponent implements OnInit {

    recentDetections$: Observable<Array<RecentDetection>>;

    constructor(private recentDetectionService: RecentDetectionService) {
    }

    ngOnInit() {
        this.recentDetections$ = Observable.interval(5000)
            .exhaustMap(() => this.recentDetectionService.getJsonFromApi())
            .do(recent => console.log(recent[0].macAddress));
    }
}

And update your view to use AsyncPipe:

<tr *ngFor="let detected of recentDetections$ | async">
    ...
</tr>

Want to add, that it's better to make a service with a method that will take interval argument, and:

  • create new requests (by using exhaustMap like in code above);
  • handle requests errors;
  • stop browser from making new requests while offline.

C++ Fatal Error LNK1120: 1 unresolved externals

You must reference it. To do this, open the shortcut menu for the project in Solution Explorer, and then choose References. In the Property Pages dialog box, expand the Common Properties node, select Framework and References, and then choose the Add New Reference button.

Append data to a POST NSURLRequest

 NSURL *url= [NSURL URLWithString:@"https://www.paypal.com/cgi-bin/webscr"];
 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:aUrl
                                                        cachePolicy:NSURLRequestUseProtocolCachePolicy
                                                    timeoutInterval:10.0];
[request setHTTPMethod:@"POST"];
 NSString *postString = @"userId=2323";
[request setHTTPBody:[postString dataUsingEncoding:NSUTF8StringEncoding]];

How to install wget in macOS?

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

And then install wget with brew and also enable openressl for TLS support

brew install wget --with-libressl

It worked perfectly for me.

jQuery $.ajax request of dataType json will not retrieve data from PHP script

I think I know this one...

Try sending your JSON as JSON by using PHP's header() function:

/**
 * Send as JSON
 */
header("Content-Type: application/json", true);

Though you are passing valid JSON, jQuery's $.ajax doesn't think so because it's missing the header.

jQuery used to be fine without the header, but it was changed a few versions back.

ALSO

Be sure that your script is returning valid JSON. Use Firebug or Google Chrome's Developer Tools to check the request's response in the console.

UPDATE

You will also want to update your code to sanitize the $_POST to avoid sql injection attacks. As well as provide some error catching.

if (isset($_POST['get_member'])) {

    $member_id = mysql_real_escape_string ($_POST["get_member"]);

    $query = "SELECT * FROM `members` WHERE `id` = '" . $member_id . "';";

    if ($result = mysql_query( $query )) {

       $row = mysql_fetch_array($result);

       $type = $row['type'];
       $name = $row['name'];
       $fname = $row['fname'];
       $lname = $row['lname'];
       $email = $row['email'];
       $phone = $row['phone'];
       $website = $row['website'];
       $image = $row['image'];

       /* JSON Row */
       $json = array( "type" => $type, "name" => $name, "fname" => $fname, "lname" => $lname, "email" => $email, "phone" => $phone, "website" => $website, "image" => $image );

    } else {

        /* Your Query Failed, use mysql_error to report why */
        $json = array('error' => 'MySQL Query Error');

    }

     /* Send as JSON */
     header("Content-Type: application/json", true);

    /* Return JSON */
    echo json_encode($json);

    /* Stop Execution */
    exit;

}

Find JavaScript function definition in Chrome

in Chrome console:

debug(MyFunction)
MyFunction()

Does C have a string type?

There is no string type in C. You have to use char arrays.

By the way your code will not work ,because the size of the array should allow for the whole array to fit in plus one additional zero terminating character.

Difference between \w and \b regular expression meta characters

\b <= this is a word boundary.

Matches at a position that is followed by a word character but not preceded by a word character, or that is preceded by a word character but not followed by a word character.

\w <= stands for "word character". 

It always matches the ASCII characters [A-Za-z0-9_]

Is there anything specific you are trying to match?

Some useful regex websites for beginners or just to wet your appetite.

I found this to be a very useful book:

How do I make the first letter of a string uppercase in JavaScript?

Try with the following function:

function capitalize (string) {
  return [].map.call(string, (char, i) => i ? char : char.toUpperCase()).join('')
}

Usage:

capitalize('hello, world!')

Result:

Hello, world!

Convert a python UTC datetime to a local datetime using only python standard library?

In Python 3.3+:

from datetime import datetime, timezone

def utc_to_local(utc_dt):
    return utc_dt.replace(tzinfo=timezone.utc).astimezone(tz=None)

In Python 2/3:

import calendar
from datetime import datetime, timedelta

def utc_to_local(utc_dt):
    # get integer timestamp to avoid precision lost
    timestamp = calendar.timegm(utc_dt.timetuple())
    local_dt = datetime.fromtimestamp(timestamp)
    assert utc_dt.resolution >= timedelta(microseconds=1)
    return local_dt.replace(microsecond=utc_dt.microsecond)

Using pytz (both Python 2/3):

import pytz

local_tz = pytz.timezone('Europe/Moscow') # use your local timezone name here
# NOTE: pytz.reference.LocalTimezone() would produce wrong result here

## You could use `tzlocal` module to get local timezone on Unix and Win32
# from tzlocal import get_localzone # $ pip install tzlocal

# # get local timezone    
# local_tz = get_localzone()

def utc_to_local(utc_dt):
    local_dt = utc_dt.replace(tzinfo=pytz.utc).astimezone(local_tz)
    return local_tz.normalize(local_dt) # .normalize might be unnecessary

Example

def aslocaltimestr(utc_dt):
    return utc_to_local(utc_dt).strftime('%Y-%m-%d %H:%M:%S.%f %Z%z')

print(aslocaltimestr(datetime(2010,  6, 6, 17, 29, 7, 730000)))
print(aslocaltimestr(datetime(2010, 12, 6, 17, 29, 7, 730000)))
print(aslocaltimestr(datetime.utcnow()))

Output

Python 3.3
2010-06-06 21:29:07.730000 MSD+0400
2010-12-06 20:29:07.730000 MSK+0300
2012-11-08 14:19:50.093745 MSK+0400
Python 2
2010-06-06 21:29:07.730000 
2010-12-06 20:29:07.730000 
2012-11-08 14:19:50.093911 
pytz
2010-06-06 21:29:07.730000 MSD+0400
2010-12-06 20:29:07.730000 MSK+0300
2012-11-08 14:19:50.146917 MSK+0400

Note: it takes into account DST and the recent change of utc offset for MSK timezone.

I don't know whether non-pytz solutions work on Windows.

React-Router: No Not Found Route?

In newer versions of react-router you want to wrap the routes in a Switch which only renders the first matched component. Otherwise you would see multiple components rendered.

For example:

import React from 'react';
import ReactDOM from 'react-dom';
import {
  BrowserRouter as Router,
  Route,
  browserHistory,
  Switch
} from 'react-router-dom';

import App from './app/App';
import Welcome from './app/Welcome';
import NotFound from './app/NotFound';

const Root = () => (
  <Router history={browserHistory}>
    <Switch>
      <Route exact path="/" component={App}/>
      <Route path="/welcome" component={Welcome}/>
      <Route component={NotFound}/>
    </Switch>
  </Router>
);

ReactDOM.render(
  <Root/>,
  document.getElementById('root')
);

Get Month name from month number

You can also do this to get current Month :

string monthName = CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(DateTime.Now.Month);

What are the recommendations for html <base> tag?

I've never really seen a point in using it. Provides very little advantage, and might even make things harder to use.

Unless you happen to have hundreds or thousands of links, all to the same sub-directory. Then it might save you a few bytes of bandwidth.

As an afterthought, I seem to recall there being some problem with the tag in IE6. You could place them anywhere in the body, redirecting different portions of the site to different locations. This was fixed in IE7, which broke a lot of sites.

Convert Enum to String

Simple: enum names into a List:

List<String> NameList = Enum.GetNames(typeof(YourEnumName)).Cast<string>().ToList()

How to select unique records by SQL

Select Eff_st from ( select EFF_ST,ROW_NUMBER() over(PARTITION BY eff_st) XYZ - from ABC.CODE_DIM

) where XYZ= 1 order by EFF_ST fetch first 5 row only

What's the difference between faking, mocking, and stubbing?

stub and fake are objects in that they can vary their response based on input parameters. the main difference between them is that a Fake is closer to a real-world implementation than a stub. Stubs contain basically hard-coded responses to an expected request. Let see an example:

public class MyUnitTest {

 @Test
 public void testConcatenate() {
  StubDependency stubDependency = new StubDependency();
  int result = stubDependency.toNumber("one", "two");
  assertEquals("onetwo", result);
 }
}

public class StubDependency() {
 public int toNumber(string param) {
  if (param == “one”) {
   return 1;
  }
  if (param == “two”) {
   return 2;
  }
 }
}

A mock is a step up from fakes and stubs. Mocks provide the same functionality as stubs but are more complex. They can have rules defined for them that dictate in what order methods on their API must be called. Most mocks can track how many times a method was called and can react based on that information. Mocks generally know the context of each call and can react differently in different situations. Because of this, mocks require some knowledge of the class they are mocking. a stub generally cannot track how many times a method was called or in what order a sequence of methods was called. A mock looks like:

public class MockADependency {

 private int ShouldCallTwice;
 private boolean ShouldCallAtEnd;
 private boolean ShouldCallFirst;

 public int StringToInteger(String s) {
  if (s == "abc") {
   return 1;
  }
  if (s == "xyz") {
   return 2;
  }
  return 0;
 }

 public void ShouldCallFirst() {
  if ((ShouldCallTwice > 0) || ShouldCallAtEnd)
   throw new AssertionException("ShouldCallFirst not first thod called");
  ShouldCallFirst = true;
 }

 public int ShouldCallTwice(string s) {
  if (!ShouldCallFirst)
   throw new AssertionException("ShouldCallTwice called before ShouldCallFirst");
  if (ShouldCallAtEnd)
   throw new AssertionException("ShouldCallTwice called after ShouldCallAtEnd");
  if (ShouldCallTwice >= 2)
   throw new AssertionException("ShouldCallTwice called more than twice");
  ShouldCallTwice++;
  return StringToInteger(s);
 }

 public void ShouldCallAtEnd() {
  if (!ShouldCallFirst)
   throw new AssertionException("ShouldCallAtEnd called before ShouldCallFirst");
  if (ShouldCallTwice != 2) throw new AssertionException("ShouldCallTwice not called twice");
  ShouldCallAtEnd = true;
 }

}

Convert DateTime to TimeSpan

In case you are using WPF and Xceed's TimePicker (which seems to be using DateTime?) as a timespan picker -as I do right now- you can get the total milliseconds (or a TimeSpan) out of it like so:

var milliseconds = DateTimeToTimeSpan(timePicker.Value).TotalMilliseconds;

    TimeSpan DateTimeToTimeSpan(DateTime? ts)
    {
        if (!ts.HasValue) return TimeSpan.Zero;
        else return new TimeSpan(0, ts.Value.Hour, ts.Value.Minute, ts.Value.Second, ts.Value.Millisecond);
    }

XAML :

<Xceed:TimePicker x:Name="timePicker" Format="Custom" FormatString="H'h 'm'm 's's'" />

If not, I guess you could just adjust my DateTimeToTimeSpan() so that it also takes 'days' into account or do sth like dateTime.Substract(DateTime.MinValue).TotalMilliseconds.

Error :The remote server returned an error: (401) Unauthorized

I add credentials for HttpWebRequest.

myReq.UseDefaultCredentials = true;
myReq.PreAuthenticate = true;
myReq.Credentials = CredentialCache.DefaultCredentials;

Why is volatile needed in C?

Volatile tells the compiler not to optimize anything that has to do with the volatile variable.

There are at least three common reasons to use it, all involving situations where the value of the variable can change without action from the visible code: When you interface with hardware that changes the value itself; when there's another thread running that also uses the variable; or when there's a signal handler that might change the value of the variable.

Let's say you have a little piece of hardware that is mapped into RAM somewhere and that has two addresses: a command port and a data port:

typedef struct
{
  int command;
  int data;
  int isbusy;
} MyHardwareGadget;

Now you want to send some command:

void SendCommand (MyHardwareGadget * gadget, int command, int data)
{
  // wait while the gadget is busy:
  while (gadget->isbusy)
  {
    // do nothing here.
  }
  // set data first:
  gadget->data    = data;
  // writing the command starts the action:
  gadget->command = command;
}

Looks easy, but it can fail because the compiler is free to change the order in which data and commands are written. This would cause our little gadget to issue commands with the previous data-value. Also take a look at the wait while busy loop. That one will be optimized out. The compiler will try to be clever, read the value of isbusy just once and then go into an infinite loop. That's not what you want.

The way to get around this is to declare the pointer gadget as volatile. This way the compiler is forced to do what you wrote. It can't remove the memory assignments, it can't cache variables in registers and it can't change the order of assignments either:

This is the correct version:

   void SendCommand (volatile MyHardwareGadget * gadget, int command, int data)
    {
      // wait while the gadget is busy:
      while (gadget->isbusy)
      {
        // do nothing here.
      }
      // set data first:
      gadget->data    = data;
      // writing the command starts the action:
      gadget->command = command;
    }

Set Icon Image in Java

Use Default toolkit for this

frame.setIconImage(Toolkit.getDefaultToolkit().getImage("Icon.png"));

How can I merge two commits into one if I already started rebase?

I often use git reset --mixed to revert a base version before multiple commits which you want to merge, then I make a new commit, that way could let your commit newest, assure your version is HEAD after you push to server.

commit ac72a4308ba70cc42aace47509a5e
Author: <[email protected]>
Date:   Tue Jun 11 10:23:07 2013 +0500

    Added algorithms for Cosine-similarity

commit 77df2a40e53136c7a2d58fd847372
Author: <[email protected]>
Date:   Tue Jun 11 13:02:14 2013 -0700

    Set stage for similar objects

commit 249cf9392da197573a17c8426c282
Author: Ralph <[email protected]>
Date:   Thu Jun 13 16:44:12 2013 -0700

    Fixed a bug in space world automation

If I want to merge head two commits into one, first I use :

git reset --mixed 249cf9392da197573a17c8426c282

"249cf9392da197573a17c8426c282" was third version, also is your base version before you merge, after that, I make a new commit :

git add .
git commit -m 'some commit message'

It's all, hope is another way for everybody.

FYI, from git reset --help:

 --mixed
     Resets the index but not the working tree (i.e., the changed files are
     preserved but not marked for commit) and reports what has not been
     updated. This is the default action.

Are strongly-typed functions as parameters possible in TypeScript?

Here are TypeScript equivalents of some common .NET delegates:

interface Action<T>
{
    (item: T): void;
}

interface Func<T,TResult>
{
    (item: T): TResult;
}

How do I reference the input of an HTML <textarea> control in codebehind?

First make sure you have the runat="server" attribute in your textarea tag like this

<textarea id="TextArea1" cols="20" rows="2" runat="server"></textarea>

Then you can access the content via:

string body = TextArea1.value;

Send auto email programmatically

Sending email programmatically with Kotlin.

  • simple email sending, not all the other features (like attachments).
  • TLS is always on
  • Only 1 gradle email dependency needed also.

I also found this list of email POP services really helpful:

https://support.office.com/en-gb/article/pop-and-imap-email-settings-for-outlook-8361e398-8af4-4e97-b147-6c6c4ac95353

How to use:

    val auth = EmailService.UserPassAuthenticator("yourUser", "yourPass")
    val to = listOf(InternetAddress("[email protected]"))
    val from = InternetAddress("[email protected]")
    val email = EmailService.Email(auth, to, from, "Test Subject", "Hello Body World")
    val emailService = EmailService("yourSmtpServer", 587)

    GlobalScope.launch { // or however you do background threads
        emailService.send(email)
    }

The code:

import java.util.*
import javax.mail.*
import javax.mail.internet.InternetAddress
import javax.mail.internet.MimeBodyPart
import javax.mail.internet.MimeMessage
import javax.mail.internet.MimeMultipart

class EmailService(private var server: String, private var port: Int) {

    data class Email(
        val auth: Authenticator,
        val toList: List<InternetAddress>,
        val from: Address,
        val subject: String,
        val body: String
    )

    class UserPassAuthenticator(private val username: String, private val password: String) : Authenticator() {
        override fun getPasswordAuthentication(): PasswordAuthentication {
            return PasswordAuthentication(username, password)
        }
    }

    fun send(email: Email) {
        val props = Properties()
        props["mail.smtp.auth"] = "true"
        props["mail.user"] = email.from
        props["mail.smtp.host"] = server
        props["mail.smtp.port"] = port
        props["mail.smtp.starttls.enable"] = "true"
        props["mail.smtp.ssl.trust"] = server
        props["mail.mime.charset"] = "UTF-8"
        val msg: Message = MimeMessage(Session.getDefaultInstance(props, email.auth))
        msg.setFrom(email.from)
        msg.sentDate = Calendar.getInstance().time
        msg.setRecipients(Message.RecipientType.TO, email.toList.toTypedArray())
//      msg.setRecipients(Message.RecipientType.CC, email.ccList.toTypedArray())
//      msg.setRecipients(Message.RecipientType.BCC, email.bccList.toTypedArray())
        msg.replyTo = arrayOf(email.from)

        msg.addHeader("X-Mailer", CLIENT_NAME)
        msg.addHeader("Precedence", "bulk")
        msg.subject = email.subject

        msg.setContent(MimeMultipart().apply {
            addBodyPart(MimeBodyPart().apply {
                setText(email.body, "iso-8859-1")
                //setContent(email.htmlBody, "text/html; charset=UTF-8")
            })
        })
        Transport.send(msg)
    }

    companion object {
        const val CLIENT_NAME = "Android StackOverflow programmatic email"
    }
}

Gradle:

dependencies {
    implementation 'com.sun.mail:android-mail:1.6.4'
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.3"
}

AndroidManifest:

<uses-permission name="android.permission.INTERNET" />

Node.js https pem error: routines:PEM_read_bio:no start line

I faced with the problem like this.

The problem was that I added the public key without '-----BEGIN PUBLIC KEY-----' at the beginning and without '-----END PUBLIC KEY-----'.

So it causes the error.

Initially, my public key was like this:

-----BEGIN PUBLIC KEY-----
WnsbGUXbb0GbJSCwCBAhrzT0s2KMRyqqS7QBiIG7t3H2Qtmde6UoUIcTTPJgv71
......
oNLcaK2wKKyRdcROK7ZTSCSMsJpAFOY
-----END PUBLIC KEY-----

But I used just this part:

WnsbGUXb+b0GbJSCwCBAhrzT0s2KMRyqqS7QBiIG7t3H2Qtmde6UoUIcTTPJgv71
......
oNLcaK2w+KKyRdcROK7ZTSCSMsJpAFOY

How can I delete a user in linux when the system says its currently used in a process

restart your computer and run $sudo deluser username... worked for me

Non greedy (reluctant) regex matching in sed?

Non-greedy solution for more than a single character

This thread is really old but I assume people still needs it. Lets say you want to kill everything till the very first occurrence of HELLO. You cannot say [^HELLO]...

So a nice solution involves two steps, assuming that you can spare a unique word that you are not expecting in the input, say top_sekrit.

In this case we can:

s/HELLO/top_sekrit/     #will only replace the very first occurrence
s/.*top_sekrit//        #kill everything till end of the first HELLO

Of course, with a simpler input you could use a smaller word, or maybe even a single character.

HTH!

What is PAGEIOLATCH_SH wait type in SQL Server?

From Microsoft documentation:

PAGEIOLATCH_SH

Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Shared mode. Long waits may indicate problems with the disk subsystem.

In practice, this almost always happens due to large scans over big tables. It almost never happens in queries that use indexes efficiently.

If your query is like this:

Select * from <table> where <col1> = <value> order by <PrimaryKey>

, check that you have a composite index on (col1, col_primary_key).

If you don't have one, then you'll need either a full INDEX SCAN if the PRIMARY KEY is chosen, or a SORT if an index on col1 is chosen.

Both of them are very disk I/O consuming operations on large tables.

iOS 7 App Icons, Launch images And Naming Convention While Keeping iOS 6 Icons

You should use Asset Catalog:

I have investigated, how we can use Asset Catalog; Now it seems to be easy for me. I want to show you steps to add icons and splash in asset catalog.

Note: No need to make any entry in info.plist file :) And no any other configuration.

In below image, at right side, you will see highlighted area, where you can mention which icons you need. In case of mine, i have selected first four checkboxes; As its for my app requirements. You can select choices according to your requirements.

enter image description here

Now, see below image. As you will select any App icon then you will see its detail at right side selected area. It will help you to upload correct resolution icon. enter image description here

If Correct resolution image will not be added then following warning will come. Just upload the image with correct resolution. enter image description here

After uploading all required dimensions, you shouldn't get any warning. enter image description here

Windows error 2 occured while loading the Java VM

For me it works a deleting "C:\ProgramData\Oracle\Java\javapath" in my system enviroment PATH variable

Edit: If you don't have that variable or it does not work you can directly delete or rename the directory "C:\ProgramData\Oracle\Java\javapath"

Beginner question: returning a boolean value from a function in Python

Ignoring the refactoring issues, you need to understand functions and return values. You don't need a global at all. Ever. You can do this:

def rps():
    # Code to determine if player wins
    if player_wins:
        return True

    return False

Then, just assign a value to the variable outside this function like so:

player_wins = rps()

It will be assigned the return value (either True or False) of the function you just called.


After the comments, I decided to add that idiomatically, this would be better expressed thus:

 def rps(): 
     # Code to determine if player wins, assigning a boolean value (True or False)
     # to the variable player_wins.

     return player_wins

 pw = rps()

This assigns the boolean value of player_wins (inside the function) to the pw variable outside the function.

Set a button background image iPhone programmatically

When setting an image in a tableViewCell or collectionViewCell, this worked for me:

Place the following code in your cellForRowAtIndexPath or cellForItemAtIndexPath

// Obtain pointer to cell. Answer assumes that you've done this, but here for completeness.

CheeseCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cheeseCell" forIndexPath:indexPath];

// Grab the image from document library and set it to the cell.

UIImage *myCheese = [UIImage imageNamed:@"swissCheese.png"];
[cell.cheeseThumbnail setImage:myCheese forState:UIControlStateNormal];

NOTE: xCode seemed to get hung up on this for me. I had to restart both xCode and the Simulator, it worked properly.

This assumes that you've got cheeseThumbnail set up as an IBOutlet... and some other stuff... hopefully you're familiar enough with table/collection views and can fit this in.

Hope this helps.

How to connect Robomongo to MongoDB

If there is no authentication enabled (username/password) and still unable to connect. Just use localhost and default port. Click Test and Save, if test connection is successful.

enter image description here

enter image description here

enter image description here

enter image description here

Regards Jagdish

when exactly are we supposed to use "public static final String"?

Why do people use constants in classes instead of a variable?

readability and maintainability,

having some number like 40.023 in your code doesn't say much about what the number represents, so we replace it by a word in capitals like "USER_AGE_YEARS". Later when we look at the code its clear what that number represents.

Why do we not just use a variable? Well we would if we knew the number would change, but if its some number that wont change, like 3.14159.. we make it final.

But what if its not a number like a String? In that case its mostly for maintainability, if you are using a String multiple times in your code, (and it wont be changing at runtime) it is convenient to have it as a final string at the top of the class. That way when you want to change it, there is only one place to change it rather than many.

For example if you have an error message that get printed many times in your code, having final String ERROR_MESSAGE = "Something went bad." is easier to maintain, if you want to change it from "Something went bad." to "It's too late jim he's already dead", you would only need to change that one line, rather than all the places you would use that comment.

Convert an array to string

You can join your array using the following:

string.Join(",", Client);

Then you can output anyway you want. You can change the comma to what ever you want, a space, a pipe, or whatever.

Removing rounded corners from a <select> element in Chrome/Webkit

Solution with custom right drop-down arrow, uses only css (no images)

_x000D_
_x000D_
select {_x000D_
  -webkit-appearance: none;_x000D_
  -webkit-border-radius: 0px;_x000D_
  background-image: linear-gradient(45deg, transparent 50%, gray 50%), linear-gradient(135deg, gray 50%, transparent 50%);_x000D_
  background-position: calc(100% - 20px) calc(1em + 2px), calc(100% - 15px) calc(1em + 2px), calc(100% - 2.5em) 0.5em;_x000D_
  background-size: 5px 5px, 5px 5px, 1px 1.5em;_x000D_
  background-repeat: no-repeat;_x000D_
_x000D_
  -moz-appearance: none;_x000D_
  display: block;_x000D_
  padding: 0.3rem;_x000D_
  height: 2rem;_x000D_
  width: 100%;_x000D_
}
_x000D_
<html>_x000D_
_x000D_
<body>_x000D_
  <br/>_x000D_
  <h4>Example</h4>_x000D_
  <select>_x000D_
    <option></option>_x000D_
    <option>Hello</option>_x000D_
    <option>World</option>_x000D_
  </select>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Unit Tests not discovered in Visual Studio 2017

Just had this problem with visual studio being unable to find my tests, couldn't see the button to run them besides the method, and they weren't picked up by running all tests in the project.

Turns out my test class wasn't public! Making it public allowed VS to discover the tests.

Collision resolution in Java HashMap

It could have formed a linked list, indeed. It's just that Map contract requires it to replace the entry:

V put(K key, V value)

Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

http://docs.oracle.com/javase/6/docs/api/java/util/Map.html

For a map to store lists of values, it'd need to be a Multimap. Here's Google's: http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/Multimap.html

A collection similar to a Map, but which may associate multiple values with a single key. If you call put(K, V) twice, with the same key but different values, the multimap contains mappings from the key to both values.

Edit: Collision resolution

That's a bit different. A collision happens when two different keys happen to have the same hash code, or two keys with different hash codes happen to map into the same bucket in the underlying array.

Consider HashMap's source (bits and pieces removed):

public V put(K key, V value) {
    int hash = hash(key.hashCode());
    int i = indexFor(hash, table.length);
    // i is the index where we want to insert the new element
    addEntry(hash, key, value, i);
    return null;
}

void addEntry(int hash, K key, V value, int bucketIndex) {
    // take the entry that's already in that bucket
    Entry<K,V> e = table[bucketIndex];
    // and create a new one that points to the old one = linked list
    table[bucketIndex] = new Entry<>(hash, key, value, e);
}

For those who are curious how the Entry class in HashMap comes to behave like a list, it turns out that HashMap defines its own static Entry class which implements Map.Entry. You can see for yourself by viewing the source code:

GrepCode for HashMap

c# why can't a nullable int be assigned null as a value

Similarly I did for long:

myLongVariable = (!string.IsNullOrEmpty(cbLong.SelectedItem.Value)) ? Convert.ToInt64(cbLong.SelectedItem.Value) : (long?)null;

Confusion: @NotNull vs. @Column(nullable = false) with JPA and Hibernate

The JPA @Column Annotation

The nullable attribute of the @Column annotation has two purposes:

  • it's used by the schema generation tool
  • it's used by Hibernate during flushing the Persistence Context

Schema Generation Tool

The HBM2DDL schema generation tool translates the @Column(nullable = false) entity attribute to a NOT NULL constraint for the associated table column when generating the CREATE TABLE statement.

As I explained in the Hibernate User Guide, it's better to use a tool like Flyway instead of relying on the HBM2DDL mechanism for generating the database schema.

Persistence Context Flush

When flushing the Persistence Context, Hibernate ORM also uses the @Column(nullable = false) entity attribute:

new Nullability( session ).checkNullability( values, persister, true );

If the validation fails, Hibernate will throw a PropertyValueException, and prevents the INSERT or UPDATE statement to be executed needesly:

if ( !nullability[i] && value == null ) {
    //check basic level one nullablilty
    throw new PropertyValueException(
            "not-null property references a null or transient value",
            persister.getEntityName(),
            persister.getPropertyNames()[i]
        );    
}

The Bean Validation @NotNull Annotation

The @NotNull annotation is defined by Bean Validation and, just like Hibernate ORM is the most popular JPA implementation, the most popular Bean Validation implementation is the Hibernate Validator framework.

When using Hibernate Validator along with Hibernate ORM, Hibernate Validator will throw a ConstraintViolation when validating the entity.

How to pause in C?

Good job I remembered about DOS Batch files. Don't need Getchar() at all. Just write the batch file to change directory (cd) to the folder where the program resides. type the name of the exe program and on the next line type pause. example:

cd\

wallpaper_calculator.exe pause

TokenMismatchException in VerifyCsrfToken.php Line 67

Are you redirecting it back after the post ? I had this issue and I was able to solve it by returning the same view instead of using the Redirect::back().

Use this return view()->with(), instead of Redirect::back().

How can I split a delimited string into an array in PHP?

In simple way you can go with explode($delimiter, $string);

But in a broad way, with Manual Programming :

        $string = "ab,cdefg,xyx,ht623";
        $resultArr = [];
        $strLength = strlen($string);
        $delimiter = ',';
        $j = 0;
        $tmp = '';
        for ($i = 0; $i < $strLength; $i++) {
            if($delimiter === $string[$i]) {
                $j++;
                $tmp = '';
                continue;
            }
            $tmp .= $string[$i];
            $resultArr[$j] = $tmp;
        }

Outpou : print_r($resultArr);

Array
(
    [0] => ab
    [1] => cdefg
    [2] => xyx
    [3] => ht623
)

HtmlEncode from Class Library

If you are using C#3 a good tip is to create an extension method to make this even simpler. Just create a static method (preferably in a static class) like so:

public static class Extensions
{
    public static string HtmlEncode(this string s)
    {
        return HttpUtility.HtmlEncode(s);
    }
}

You can then do neat stuff like this:

string encoded = "<div>I need encoding</div>".HtmlEncode();

Print array without brackets and commas

You can use join method from android.text.TextUtils class like:

TextUtils.join("",array);

How to make join queries using Sequelize on Node.js

Model1.belongsTo(Model2, { as: 'alias' })

Model1.findAll({include: [{model: Model2  , as: 'alias'  }]},{raw: true}).success(onSuccess).error(onError);

How to remove unwanted space between rows and columns in table?

Adding to vectran's answer: You also have to set cellspacing attribute on the table element for cross-browser compatibility.

<table cellspacing="0">

EDIT (for the sake of completeness I'm expanding this 5 years later:):

Internet Explorer 6 and Internet Explorer 7 required you to set cellspacing directly as a table attribute, otherwise the spacing wouldn't vanish.

Internet Explorer 8 and later versions and all other versions of popular browsers - Chrome, Firefox, Opera 4+ - support the CSS property border-spacing.

So in order to make a cross-browser table cell spacing reset (supporting IE6 as a dinosaur browser), you can follow the below code sample:

_x000D_
_x000D_
table{_x000D_
  border: 1px solid black;_x000D_
}_x000D_
table td {_x000D_
  border: 1px solid black; /* Style just to show the table cell boundaries */_x000D_
}_x000D_
_x000D_
_x000D_
table.no-spacing {_x000D_
  border-spacing:0; /* Removes the cell spacing via CSS */_x000D_
  border-collapse: collapse;  /* Optional - if you don't want to have double border where cells touch */_x000D_
}
_x000D_
<p>Default table:</p>_x000D_
_x000D_
<table>_x000D_
  <tr>_x000D_
    <td>First cell</td>_x000D_
    <td>Second cell</td>_x000D_
  </tr>_x000D_
</table>_x000D_
_x000D_
<p>Removed spacing:</p>_x000D_
_x000D_
<table class="no-spacing" cellspacing="0"> <!-- cellspacing 0 to support IE6 and IE7 -->_x000D_
  <tr>_x000D_
    <td>First cell</td>_x000D_
    <td>Second cell</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Boolean checking in the 'if' condition

First style is better. Though you should use better variable name

How do I make background-size work in IE?

There is a good polyfill for that: louisremi/background-size-polyfill

To quote the documentation:

Upload backgroundsize.min.htc to your website, along with the .htaccess that will send the mime-type required by IE (Apache only — it's built in nginx, node and IIS).

Everywhere you use background-size in your CSS, add a reference to this file.

.selector { 
    background-size: cover;
    /* The url is relative to the document, not to the css file! */
    /* Prefer absolute urls to avoid confusion. */
    -ms-behavior: url(/backgroundsize.min.htc);
}

127 Return code from $?

If you're trying to run a program using a scripting language, you may need to include the full path of the scripting language and the file to execute. For example:

exec('/usr/local/bin/node /usr/local/lib/node_modules/uglifycss/uglifycss in.css > out.css');

In Gradle, is there a better way to get Environment Variables?

In android gradle 0.4.0 you can just do:

println System.env.HOME

classpath com.android.tools.build:gradle-experimental:0.4.0

How to insert a column in a specific position in oracle without dropping and recreating the table?

You (still) can not choose the position of the column using ALTER TABLE: it can only be added to the end of the table. You can obviously select the columns in any order you want, so unless you are using SELECT * FROM column order shouldn't be a big deal.

If you really must have them in a particular order and you can't drop and recreate the table, then you might be able to drop and recreate columns instead:-

First copy the table

CREATE TABLE my_tab_temp AS SELECT * FROM my_tab;

Then drop columns that you want to be after the column you will insert

ALTER TABLE my_tab DROP COLUMN three;

Now add the new column (two in this example) and the ones you removed.

ALTER TABLE my_tab ADD (two NUMBER(2), three NUMBER(10));

Lastly add back the data for the re-created columns

UPDATE my_tab SET my_tab.three = (SELECT my_tab_temp.three FROM my_tab_temp WHERE my_tab.one = my_tab_temp.one);

Obviously your update will most likely be more complex and you'll have to handle indexes and constraints and won't be able to use this in some cases (LOB columns etc). Plus this is a pretty hideous way to do this - but the table will always exist and you'll end up with the columns in a order you want. But does column order really matter that much?

Can two Java methods have same name with different return types?

Only if their parameter declarations are different from memory.

XPath OR operator for different nodes

If you want to select only one of two nodes with union operator, you can use this solution: (//bookstore/book/title | //bookstore/city/zipcode/title)[1]

Get class labels from Keras functional model

You must use the labels index you have, here what I do for text classification:

# data labels = [1, 2, 1...]
labels_index = { "website" : 0, "money" : 1 ....} 
# to feed model
label_categories = to_categorical(np.asarray(labels)) 

Then, for predictions:

texts = ["hello, rejoins moi sur skype", "bonjour comment ça va ?", "tu me donnes de l'argent"]

sequences = tokenizer.texts_to_sequences(texts)

data = pad_sequences(sequences, maxlen=MAX_SEQUENCE_LENGTH)

predictions = model.predict(data)

t = 0

for text in texts:
    i = 0
    print("Prediction for \"%s\": " % (text))
    for label in labels_index:
        print("\t%s ==> %f" % (label, predictions[t][i]))
        i = i + 1
    t = t + 1

This gives:

Prediction for "hello, rejoins moi sur skype": 
    website ==> 0.759483
    money ==> 0.037091
    under ==> 0.010587
    camsite ==> 0.114436
    email ==> 0.075975
    abuse ==> 0.002428
Prediction for "bonjour comment ça va ?": 
    website ==> 0.433079
    money ==> 0.084878
    under ==> 0.048375
    camsite ==> 0.036674
    email ==> 0.369197
    abuse ==> 0.027798
Prediction for "tu me donnes de l'argent": 
    website ==> 0.006223
    money ==> 0.095308
    under ==> 0.003586
    camsite ==> 0.003115
    email ==> 0.884112
    abuse ==> 0.007655

What is the difference between CloseableHttpClient and HttpClient in Apache HttpClient API?

In the next major version of the library HttpClient interface is going to extend Closeable. Until then it is recommended to use CloseableHttpClient if compatibility with earlier 4.x versions (4.0, 4.1 and 4.2) is not required.

How to Logout of an Application Where I Used OAuth2 To Login With Google?

Ouath just makes the Google instance null, hence it you out of Google. Now that's how the architecture is made. Logging out of Google, if you Logout of your app is a dirty work, but can't help if the requirement stipulates the same. Hence add the following to your signOut() function. My project was an Angular 6 app:

document.location.href = "https://www.google.com/accounts/Logout?continue=https://appengine.google.com/_ah/logout?continue=http://localhost:4200";

Here localhost:4200 is the URL of my app. If your login page is xyz.com then input that.

How to open specific tab of bootstrap nav tabs on click of a particuler link using jQuery?

I wrote this snippet, that I've been using for handling this exact case.

It's in plain javascript, making it also suitable in cases like with bootsrap5 without jQuery.

<script type='text/javascript'>
    window.onhashchange=hashTriggerTab;
    window.onload=hashTriggerTab;
    
    function hashTriggerTab(){
        var current_hash=window.location.hash;
        if(current_hash.substring(0,1)=='#')current_hash=current_hash.substring(1);
        if(current_hash!=''){
            var trigger=document.querySelector('.nav-tabs a[href="#'+current_hash+'"]');
            if(trigger)trigger.click();
        }
    }
</script>

With that in place, you could link both on the same page, like:

<a href='#tabId'>Link Any Tab</a>

Or from external page like:

<a href='newpage.php#tabId'>Link From External</a>

Setting "checked" for a checkbox with jQuery

For overall:

$("#checkAll").click(function(){
    $(".somecheckBoxes").prop('checked',$(this).prop('checked')?true:false);
});

jQuery textbox change event

There is no real solution to this - even in the links to other questions given above. In the end I have decided to use setTimeout and call a method that checks every second! Not an ideal solution, but a solution that works and code I am calling is simple enough to not have an effect on performance by being called all the time.

function InitPageControls() {
        CheckIfChanged();
    }

    function CheckIfChanged() {
        // do logic

        setTimeout(function () {
            CheckIfChanged();
        }, 1000);
    }

Hope this helps someone in the future as it seems there is no surefire way of acheiving this using event handlers...

Simplest way to do a recursive self-join?

Check following to help the understand the concept of CTE recursion

DECLARE
@startDate DATETIME,
@endDate DATETIME

SET @startDate = '11/10/2011'
SET @endDate = '03/25/2012'

; WITH CTE AS (
    SELECT
        YEAR(@startDate) AS 'yr',
        MONTH(@startDate) AS 'mm',
        DATENAME(mm, @startDate) AS 'mon',
        DATEPART(d,@startDate) AS 'dd',
        @startDate 'new_date'
    UNION ALL
    SELECT
        YEAR(new_date) AS 'yr',
        MONTH(new_date) AS 'mm',
        DATENAME(mm, new_date) AS 'mon',
        DATEPART(d,@startDate) AS 'dd',
        DATEADD(d,1,new_date) 'new_date'
    FROM CTE
    WHERE new_date < @endDate
    )
SELECT yr AS 'Year', mon AS 'Month', count(dd) AS 'Days'
FROM CTE
GROUP BY mon, yr, mm
ORDER BY yr, mm
OPTION (MAXRECURSION 1000)

EF LINQ include multiple and nested entities

Include is a part of fluent interface, so you can write multiple Include statements each following other

 db.Courses.Include(i => i.Modules.Select(s => s.Chapters))
           .Include(i => i.Lab)
           .Single(x => x.Id == id); 

React / JSX Dynamic Component Name

I figured out a new solution. Do note that I am using ES6 modules so I am requiring the class. You could also define a new React class instead.

var components = {
    example: React.createFactory( require('./ExampleComponent') )
};

var type = "example";

newComponent() {
    return components[type]({ attribute: "value" });
}

how to release localhost from Error: listen EADDRINUSE

ps -ef |grep node find app.js , kill pid of app.js

Simplest way to throw an error/exception with a custom message in Swift 2?

Simplest solution without extra extensions, enums, classes and etc.:

NSException(name:NSExceptionName(rawValue: "name"), reason:"reason", userInfo:nil).raise()

How can I find out if an .EXE has Command-Line Options?

Just use IDA PRO (https://www.hex-rays.com/products/ida/index.shtml) to disassemble the file, and search for some known command line option (using Search...Text) - in that section you will then typically see all the command line options - for the program (LIB2NIST.exe) in the screenshot below, for example, it shows a documented command line option (/COM2TAG) but also some undocumented ones, like /L. Hope this helps?

enter image description here

Casting string to enum

.NET 4.0+ has a generic Enum.TryParse

ContentEnum content;
Enum.TryParse(fileContentMessage, out content);

Removing Conda environment

if you are in base:

(base) HP-Compaq-Elite-8300-CMT:~$ 

remove env_name by:

conda env remove -n env_name

if you are already in env_name environment :

(env_name) HP-Compaq-Elite-8300-CMT:~$ 

deactivate then remove by :

conda deactivate
conda env remove -n env_name

How does RewriteBase work in .htaccess

The clearest explanation I found was not in the current 2.4 apache docs, but in version 2.0.

#  /abc/def/.htaccess -- per-dir config file for directory /abc/def
#  Remember: /abc/def is the physical path of /xyz, i.e., the server
#            has a 'Alias /xyz /abc/def' directive e.g.

RewriteEngine On

#  let the server know that we were reached via /xyz and not
#  via the physical path prefix /abc/def
RewriteBase   /xyz

How does it work? For you apache hackers, this 2.0 doc goes on to give "detailed information about the internal processing steps."

Lesson learned: While we need to be familiar with "current," gems can be found in the annals.

MVC4 input field placeholder

I did so

Field in model:

[Required]
[Display(Name = "User name")]
public string UserName { get; set; }

Razor:

<li>
  @Html.TextBoxFor(m => m.UserName, new { placeholder = Html.DisplayNameFor(n => n.UserName)})
</li>

How to cast an object in Objective-C

Sure, the syntax is exactly the same as C - NewObj* pNew = (NewObj*)oldObj;

In this situation you may wish to consider supplying this list as a parameter to the constructor, something like:

// SelectionListViewController
-(id) initWith:(SomeListClass*)anItemList
{
  self = [super init];

  if ( self ) {
    [self setList: anItemList];
  }

  return self;
}

Then use it like this:

myEditController = [[SelectionListViewController alloc] initWith: listOfItems];

How can I write variables inside the tasks file in ansible

Whenever you have a module followed by a variable on the same line in ansible the parser will treat the reference variable as the beginning of an in-line dictionary. For example:

- name: some example
  command: {{ myapp }} -a foo

The default here is to parse the first part of {{ myapp }} -a foo as a dictionary instead of a string and you will get an error.

So you must quote the argument like so:

- name: some example
  command: "{{ myapp }} -a foo"

How to make Firefox headless programmatically in Selenium with Python?

To the OP or anyone currently interested, here's the section of code that's worked for me with firefox currently:

opt = webdriver.FirefoxOptions()
opt.add_argument('-headless')
ffox_driver = webdriver.Firefox(executable_path='\path\to\geckodriver', options=opt)

Giving multiple URL patterns to Servlet Filter

If an URL pattern starts with /, then it's relative to the context root. The /Admin/* URL pattern would only match pages on http://localhost:8080/EMS2/Admin/* (assuming that /EMS2 is the context path), but you have them actually on http://localhost:8080/EMS2/faces/Html/Admin/*, so your URL pattern never matches.

You need to prefix your URL patterns with /faces/Html as well like so:

<url-pattern>/faces/Html/Admin/*</url-pattern>

You can alternatively also just reconfigure your web project structure/configuration so that you can get rid of the /faces/Html path in the URLs so that you can just open the page by for example http://localhost:8080/EMS2/Admin/Upload.xhtml.

Your filter mapping syntax is all fine. However, a simpler way to specify multiple URL patterns is to just use only one <filter-mapping> with multiple <url-pattern> entries:

<filter-mapping>
    <filter-name>LoginFilter</filter-name>
    <url-pattern>/faces/Html/Employee/*</url-pattern>
    <url-pattern>/faces/Html/Admin/*</url-pattern>
    <url-pattern>/faces/Html/Supervisor/*</url-pattern>
</filter-mapping>

Find and replace entire mysql database

This isn't possible - you need to carry out an UPDATE for each table individually.

WARNING: DUBIOUS, BUT IT'LL WORK (PROBABLY) SOLUTION FOLLOWS

Alternatively, you could dump the database via mysqldump and simply perform the search/replace on the resultant SQL file. (I'd recommend offlining anything that might touch the database whilst this is in progress, as well as using the --add-drop-table and --extended-insert flags.) However, you'd need to be sure that the search/replace text wasn't going to alter anything other than the data itself (i.e.: that the text you were going to swap out might not occur as a part of SQL syntax) and I'd really try doing the re-insert on an empty test database first.)

How to process a file in PowerShell line-by-line as a stream

If you are really about to work on multi-gigabyte text files then do not use PowerShell. Even if you find a way to read it faster processing of huge amount of lines will be slow in PowerShell anyway and you cannot avoid this. Even simple loops are expensive, say for 10 million iterations (quite real in your case) we have:

# "empty" loop: takes 10 seconds
measure-command { for($i=0; $i -lt 10000000; ++$i) {} }

# "simple" job, just output: takes 20 seconds
measure-command { for($i=0; $i -lt 10000000; ++$i) { $i } }

# "more real job": 107 seconds
measure-command { for($i=0; $i -lt 10000000; ++$i) { $i.ToString() -match '1' } }

UPDATE: If you are still not scared then try to use the .NET reader:

$reader = [System.IO.File]::OpenText("my.log")
try {
    for() {
        $line = $reader.ReadLine()
        if ($line -eq $null) { break }
        # process the line
        $line
    }
}
finally {
    $reader.Close()
}

UPDATE 2

There are comments about possibly better / shorter code. There is nothing wrong with the original code with for and it is not pseudo-code. But the shorter (shortest?) variant of the reading loop is

$reader = [System.IO.File]::OpenText("my.log")
while($null -ne ($line = $reader.ReadLine())) {
    $line
}

How to automatically generate a stacktrace when my program crashes

ulimit -c unlimited

is a system variable, wich will allow to create a core dump after your application crashes. In this case an unlimited amount. Look for a file called core in the very same directory. Make sure you compiled your code with debugging informations enabled!

regards

How to sanity check a date in Java

java.time

With the Date and Time API (java.time classes) built into Java 8 and later, you can use the LocalDate class.

public static boolean isDateValid(int year, int month, int day) {
    boolean dateIsValid = true;
    try {
        LocalDate.of(year, month, day);
    } catch (DateTimeException e) {
        dateIsValid = false;
    }
    return dateIsValid;
}

Can we create an instance of an interface in Java?

Yes we can, "Anonymous classes enable you to make your code more concise. They enable you to declare and instantiate a class at the same time. They are like local classes except that they do not have a name"->>Java Doc

Android Open External Storage directory(sdcard) for storing file

Try using

new File(Environment.getExternalStorageDirectory(),"somefilename");

And don't forget to add WRITE_EXTERNAL STORAGE and READ_EXTERNAL STORAGE permissions

Truncate with condition

No, TRUNCATE is all or nothing. You can do a DELETE FROM <table> WHERE <conditions> but this loses the speed advantages of TRUNCATE.

Make outer div be automatically the same height as its floating content

First of all you don't use width=300px that's an attribute setting for the tag not CSS, use width: 300px; instead.

I would suggest applying the clearfix technique on the #outerdiv. Clearfix is a general solution to clear 2 floating divs so the parent div will expand to accommodate the 2 floating divs.

<div id='outerdiv' class='clearfix' style='width:600px; background-color: black;'>
    <div style='width:300px; float: left;'>
        <p>xxxxxxxxxxxxxxxxxxxxxxxxxxxxx</p>
    </div>

    <div style='width:300px; float: left;'>
        <p>zzzzzzzzzzzzzzzzzzzzzzzzzzzzz</p>
    </div>
</div>

Here is an example of your situation and what Clearfix does to resolve it.

How to get html table td cell value by JavaScript?

Don't use in-line JavaScript, separate your behaviour from your data and it gets much easier to handle. I'd suggest the following:

var table = document.getElementById('tableID'),
    cells = table.getElementsByTagName('td');

for (var i=0,len=cells.length; i<len; i++){
    cells[i].onclick = function(){
        console.log(this.innerHTML);
        /* if you know it's going to be numeric:
        console.log(parseInt(this.innerHTML),10);
        */
    }
}

_x000D_
_x000D_
var table = document.getElementById('tableID'),_x000D_
  cells = table.getElementsByTagName('td');_x000D_
_x000D_
for (var i = 0, len = cells.length; i < len; i++) {_x000D_
  cells[i].onclick = function() {_x000D_
    console.log(this.innerHTML);_x000D_
  };_x000D_
}
_x000D_
th,_x000D_
td {_x000D_
  border: 1px solid #000;_x000D_
  padding: 0.2em 0.3em 0.1em 0.3em;_x000D_
}
_x000D_
<table id="tableID">_x000D_
  <thead>_x000D_
    <tr>_x000D_
      <th>Column heading 1</th>_x000D_
      <th>Column heading 2</th>_x000D_
      <th>Column heading 3</th>_x000D_
      <th>Column heading 4</th>_x000D_
    </tr>_x000D_
  </thead>_x000D_
  <tbody>_x000D_
    <tr>_x000D_
      <td>43</td>_x000D_
      <td>23</td>_x000D_
      <td>89</td>_x000D_
      <td>5</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>4</td>_x000D_
      <td>3</td>_x000D_
      <td>0</td>_x000D_
      <td>98</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>10</td>_x000D_
      <td>32</td>_x000D_
      <td>7</td>_x000D_
      <td>2</td>_x000D_
    </tr>_x000D_
  </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

JS Fiddle proof-of-concept.

A revised approach, in response to the comment (below):

You're missing a semicolon. Also, don't make functions within a loop.

This revision binds a (single) named function as the click event-handler of the multiple <td> elements, and avoids the unnecessary overhead of creating multiple anonymous functions within a loop (which is poor practice due to repetition and the impact on performance, due to memory usage):

function logText() {
  // 'this' is automatically passed to the named
  // function via the use of addEventListener()
  // (later):
  console.log(this.textContent);
}

// using a CSS Selector, with document.querySelectorAll()
// to get a NodeList of <td> elements within the #tableID element:
var cells = document.querySelectorAll('#tableID td');

// iterating over the array-like NodeList, using
// Array.prototype.forEach() and Function.prototype.call():
Array.prototype.forEach.call(cells, function(td) {
  // the first argument of the anonymous function (here: 'td')
  // is the element of the array over which we're iterating.

  // adding an event-handler (the function logText) to handle
  // the click events on the <td> elements:
  td.addEventListener('click', logText);
});

_x000D_
_x000D_
function logText() {_x000D_
  console.log(this.textContent);_x000D_
}_x000D_
_x000D_
var cells = document.querySelectorAll('#tableID td');_x000D_
_x000D_
Array.prototype.forEach.call(cells, function(td) {_x000D_
  td.addEventListener('click', logText);_x000D_
});
_x000D_
th,_x000D_
td {_x000D_
  border: 1px solid #000;_x000D_
  padding: 0.2em 0.3em 0.1em 0.3em;_x000D_
}
_x000D_
<table id="tableID">_x000D_
  <thead>_x000D_
    <tr>_x000D_
      <th>Column heading 1</th>_x000D_
      <th>Column heading 2</th>_x000D_
      <th>Column heading 3</th>_x000D_
      <th>Column heading 4</th>_x000D_
    </tr>_x000D_
  </thead>_x000D_
  <tbody>_x000D_
    <tr>_x000D_
      <td>43</td>_x000D_
      <td>23</td>_x000D_
      <td>89</td>_x000D_
      <td>5</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>4</td>_x000D_
      <td>3</td>_x000D_
      <td>0</td>_x000D_
      <td>98</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>10</td>_x000D_
      <td>32</td>_x000D_
      <td>7</td>_x000D_
      <td>2</td>_x000D_
    </tr>_x000D_
  </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

JS Fiddle proof-of-concept.

References:

Maven Modules + Building a Single Specific Module

Maven absolutely was designed for this type of dependency.

mvn package won't install anything in your local repository it just packages the project and leaves it in the target folder.

Do mvn install in parent project (A), with this all the sub-modules will be installed in your computer's Maven repository, if there are no changes you just need to compile/package the sub-module (B) and Maven will take the already packaged and installed dependencies just right.

You just need to a mvn install in the parent project if you updated some portion of the code.

Difference between dict.clear() and assigning {} in Python

If you have another variable also referring to the same dictionary, there is a big difference:

>>> d = {"stuff": "things"}
>>> d2 = d
>>> d = {}
>>> d2
{'stuff': 'things'}
>>> d = {"stuff": "things"}
>>> d2 = d
>>> d.clear()
>>> d2
{}

This is because assigning d = {} creates a new, empty dictionary and assigns it to the d variable. This leaves d2 pointing at the old dictionary with items still in it. However, d.clear() clears the same dictionary that d and d2 both point at.

List<Map<String, String>> vs List<? extends Map<String, String>>

What I'm missing in the other answers is a reference to how this relates to co- and contravariance and sub- and supertypes (that is, polymorphism) in general and to Java in particular. This may be well understood by the OP, but just in case, here it goes:

Covariance

If you have a class Automobile, then Car and Truck are their subtypes. Any Car can be assigned to a variable of type Automobile, this is well-known in OO and is called polymorphism. Covariance refers to using this same principle in scenarios with generics or delegates. Java doesn't have delegates (yet), so the term applies only to generics.

I tend to think of covariance as standard polymorphism what you would expect to work without thinking, because:

List<Car> cars;
List<Automobile> automobiles = cars;
// You'd expect this to work because Car is-a Automobile, but
// throws inconvertible types compile error.

The reason of the error is, however, correct: List<Car> does not inherit from List<Automobile> and thus cannot be assigned to each other. Only the generic type parameters have an inherit relationship. One might think that the Java compiler simply isn't smart enough to properly understand your scenario there. However, you can help the compiler by giving him a hint:

List<Car> cars;
List<? extends Automobile> automobiles = cars;   // no error

Contravariance

The reverse of co-variance is contravariance. Where in covariance the parameter types must have a subtype relationship, in contravariance they must have a supertype relationship. This can be considered as an inheritance upper-bound: any supertype is allowed up and including the specified type:

class AutoColorComparer implements Comparator<Automobile>
    public int compare(Automobile a, Automobile b) {
        // Return comparison of colors
    }

This can be used with Collections.sort:

public static <T> void sort(List<T> list, Comparator<? super T> c)

// Which you can call like this, without errors:
List<Car> cars = getListFromSomewhere();
Collections.sort(cars, new AutoColorComparer());

You could even call it with a comparer that compares objects and use it with any type.

When to use contra or co-variance?

A bit OT perhaps, you didn't ask, but it helps understanding answering your question. In general, when you get something, use covariance and when you put something, use contravariance. This is best explained in an answer to Stack Overflow question How would contravariance be used in Java generics?.

So what is it then with List<? extends Map<String, String>>

You use extends, so the rules for covariance applies. Here you have a list of maps and each item you store in the list must be a Map<string, string> or derive from it. The statement List<Map<String, String>> cannot derive from Map, but must be a Map.

Hence, the following will work, because TreeMap inherits from Map:

List<Map<String, String>> mapList = new ArrayList<Map<String, String>>();
mapList.add(new TreeMap<String, String>());

but this will not:

List<? extends Map<String, String>> mapList = new ArrayList<? extends Map<String, String>>();
mapList.add(new TreeMap<String, String>());

and this will not work either, because it does not satisfy the covariance constraint:

List<? extends Map<String, String>> mapList = new ArrayList<? extends Map<String, String>>();
mapList.add(new ArrayList<String>());   // This is NOT allowed, List does not implement Map

What else?

This is probably obvious, but you may have already noted that using the extends keyword only applies to that parameter and not to the rest. I.e., the following will not compile:

List<? extends Map<String, String>> mapList = new List<? extends Map<String, String>>();
mapList.add(new TreeMap<String, Element>())  // This is NOT allowed

Suppose you want to allow any type in the map, with a key as string, you can use extend on each type parameter. I.e., suppose you process XML and you want to store AttrNode, Element etc in a map, you can do something like:

List<? extends Map<String, ? extends Node>> listOfMapsOfNodes = new...;

// Now you can do:
listOfMapsOfNodes.add(new TreeMap<Sting, Element>());
listOfMapsOfNodes.add(new TreeMap<Sting, CDATASection>());

Setting width/height as percentage minus pixels

  1. Use negative margins on the element you would like to minus pixels off. (desired element)
  2. Make overflow:hidden; on the containing element
  3. Switch to overflow:auto; on the desired element.

It worked for me!

Should I learn C before learning C++?

Learning C forces you to think harder about some issues such as explicit and implicit memory management or storage sizes of basic data types at the time you write your code.

Once you have reached a point where you feel comfortable around C's features and misfeatures, you will probably have less trouble learning and writing in C++.

It is entirely possible that the C++ code you have seen did not look much different from standard C, but that may well be because it was not object oriented and did not use exceptions, object-orientation, templates or other advanced features.

Validating file types by regular expression

^.+\.(?:(?:[dD][oO][cC][xX]?)|(?:[pP][dD][fF]))$

Will accept .doc, .docx, .pdf files having a filename of at least one character:

^           = beginning of string
.+          = at least one character (any character)
\.          = dot ('.')
(?:pattern) = match the pattern without storing the match)
[dD]        = any character in the set ('d' or 'D')
[xX]?       = any character in the set or none 
              ('x' may be missing so 'doc' or 'docx' are both accepted)
|           = either the previous or the next pattern
$           = end of matched string

Warning! Without enclosing the whole chain of extensions in (?:), an extension like .docpdf would pass.

You can test regular expressions at http://www.regextester.com/

Variables as commands in bash scripts

I am not sure, but it might be worth running an eval on the commands first.

This will let bash expand the variables $TAR_CMD and such to their full breadth(just as the echo command does to the console, which you say works)

Bash will then read the line a second time with the variables expanded.

eval $TAR_CMD | $ENCRYPT_CMD | $SPLIT_CMD 

I just did a Google search and this page looks like it might do a decent job at explaining why that is needed. http://fvue.nl/wiki/Bash:_Why_use_eval_with_variable_expansion%3F

How do I specify new lines on Python, when writing on files?

It depends on how correct you want to be. \n will usually do the job. If you really want to get it right, you look up the newline character in the os package. (It's actually called linesep.)

Note: when writing to files using the Python API, do not use the os.linesep. Just use \n; Python automatically translates that to the proper newline character for your platform.

R Language: How to print the first or last rows of a data set?

If you want to print the last 10 lines, use

tail(dataset, 10)

for the first 10, you could also do

head(dataset, 10)

Postgresql : syntax error at or near "-"

Wrap it in double quotes

alter user "dell-sys" with password 'Pass@133';

Notice that you will have to use the same case you used when you created the user using double quotes. Say you created "Dell-Sys" then you will have to issue exact the same whenever you refer to that user.

I think the best you do is to drop that user and recreate without illegal identifier characters and without double quotes so you can later refer to it in any case you want.

Open a file with Notepad in C#

Use System.Diagnostics.Process to launch an instance of Notepad.exe.

Running Python from Atom

Download and Install package here: https://atom.io/packages/script

To execute the python command in atom use the below shortcuts:

For Windows/Linux, it's SHIFT + Ctrl + B OR Ctrl + SHIFT + B

If you're on Mac, press ? + I

How can I scale an entire web page with CSS?

CSS will not be able to zoom on demand, but if you couple CSS with JS, you could change some values to make a page look bigger. However, as it has been said, this feature is standard nowadays in modern browsers: no need to replicate it. As a matter of fact, replicating it will slow down your website (more things to load, more JS or CSS to parse or execute and apply, etc.)

org.apache.catalina.core.StandardContext startInternal SEVERE: Error listenerStart

For Intellij Idea sometime localhost.log file generated at different location. For e.g. you can find it at homedirectory\ .IntelliJIdea14\system\tomcat.

IF you are using spring then start ur server in debug mode and put debug point in catch block of org.springframework.context.support.AbstractApplicationContext's refresh() method. If bean creation fails you would be able to see the exception.

javascript regular expression to check for IP addresses

Try this one, it's a shorter version:

^(?!0)(?!.*\.$)((1?\d?\d|25[0-5]|2[0-4]\d)(\.|$)){4}$

Explained:

^ start of string
  (?!0)         Assume IP cannot start with 0
  (?!.*\.$)     Make sure string does not end with a dot
  (
    (
    1?\d?\d|   A single digit, two digits, or 100-199
    25[0-5]|   The numbers 250-255
    2[0-4]\d   The numbers 200-249
    )
  \.|$ the number must be followed by either a dot or end-of-string - to match the last number
  ){4}         Expect exactly four of these
$ end of string

Unit test for a browser's console:

var rx=/^(?!0)(?!.*\.$)((1?\d?\d|25[0-5]|2[0-4]\d)(\.|$)){4}$/;
var valid=['1.2.3.4','11.11.11.11','123.123.123.123','255.250.249.0','1.12.123.255','127.0.0.1','1.0.0.0'];
var invalid=['0.1.1.1','01.1.1.1','012.1.1.1','1.2.3.4.','1.2.3\n4','1.2.3.4\n','259.0.0.1','123.','1.2.3.4.5','.1.2.3.4','1,2,3,4','1.2.333.4','1.299.3.4'];
valid.forEach(function(s){if (!rx.test(s))console.log('bad valid: '+s);});
invalid.forEach(function(s){if (rx.test(s)) console.log('bad invalid: '+s);});

Mysql: Select rows from a table that are not in another

If you have 300 columns as you mentioned in another comment, and you want to compare on all columns (assuming the columns are all the same name), you can use a NATURAL LEFT JOIN to implicitly join on all matching column names between the two tables so that you don't have to tediously type out all join conditions manually:

SELECT            a.*
FROM              tbl_1 a
NATURAL LEFT JOIN tbl_2 b
WHERE             b.FirstName IS NULL

How do I add a .click() event to an image?

Enclose <img> in <a> tag.

<a href="http://www.google.com.pk"><img src="smiley.gif"></a>

it will open link on same tab, and if you want to open link on new tab then use target="_blank"

<a href="http://www.google.com.pk" target="_blank"><img src="smiley.gif"></a>

Laravel - htmlspecialchars() expects parameter 1 to be string, object given

You could use serialize

<input type="hidden" name="quotation[]" value="{{serialize($quotation)}}">

But best way in this case use the json_encode method in your blade and json_decode in controller.

Disable Drag and Drop on HTML elements?

This works. Try it.

<BODY ondragstart="return false;" ondrop="return false;">

how to display employee names starting with a and then b in sql

Here what I understood from the question is starting with "a " and then "b" ex:

  • abhay
  • abhishek
  • abhinav

So there should be two conditions and both should be true means you cant use "OR" operator Ordered by is not not compulsory but its good if you use.

Select e_name from emp 
where  e_name like 'a%' AND e_name like '_b%'
Ordered by e_name

How to set custom favicon in Express?

In app.js:

app.use(express.static(path.join(__dirname, 'public')));

Assuming the icon resides in "/public/images/favicon.ico" add next link in html's head:

<link rel='icon' href='/images/favicon.ico' class='js-favicon'>

This worked fine in a project auto-generated with the command:

express my-project

Windows Scipy Install: No Lapack/Blas Resources Found

You probably just have too new (unsupported) Python 3.x installed.

This page has overcomplicated solutions to the problem. Most of numpy / scipy users should not need to compile their numpy installations or need to rely on 3rd party "numpy+mkl" wheels.

Downloading a compiler is an anti-pattern, you do not want to build numpy, only use it. [github.com/numpy]

Solution

  • Once you have installed supported python version, remove your non-working numpy installation with
pip uninstall numpy

and install scipy with

pip install scipy --only-binary numpy
  • The --only-binary numpy will force installing binary wheel (.whl) version of numpy. If it fails, you have too new (not yet supported) version of python.

  • If you have multiple python versions installed, you can ensure that pip is installing the python version you want by

<path_to_python_executable> -m pip install <X> 

instead of pip install <X>.

Why this is happening?

  • Scipy relies on numpy, as can be seen from the setup.py or just by reading the pip install logs.
  • If you have too new (non-supported) python installation, there are no built wheel (.whl) in the pip repository, but tarballs (.tar.gz), which in this case require the user machine to compile some C++-code during installation. See also: Python packaging: wheels vs tarball (tar.gz)

Appendix

  • Check the https://pypi.org/project/numpy/ for list of supported Python versions. Currently (2020-11-04) the newest supported python version is Python 3.9. when using numpy 1.19.3 or above, and Python 3.8 for numpy 1.19.2. (For compatibility of older numpy versions, see numpy release notes)
  • If you are on Windows and see pip trying to install numpy-<x>.tag.gz, you know it probably will not work. Try older version of Python, instead. You want to see pip to installing a binary wheel for numpy for Windows (numpy-<x>.whl). You can check the wheels in pip available for numpy here.

Vim and Ctags tips and tricks

I've been adapting my vim plugins for two years to support big enough c++ project. You can take a look at them.

They use ctags and cscsope.

http://www.vim.org/scripts/script.php?script_id=1638
http://www.vim.org/scripts/script.php?script_id=2507

Under what circumstances can I call findViewById with an Options Menu / Action Bar item?

I am trying to obtain a handle on one of the views in the Action Bar

I will assume that you mean something established via android:actionLayout in your <item> element of your <menu> resource.

I have tried calling findViewById(R.id.menu_item)

To retrieve the View associated with your android:actionLayout, call findItem() on the Menu to retrieve the MenuItem, then call getActionView() on the MenuItem. This can be done any time after you have inflated the menu resource.

Stored procedure return into DataSet in C# .Net

I should tell you the basic steps and rest depends upon your own effort. You need to perform following steps.

  • Create a connection string.
  • Create a SQL connection
  • Create SQL command
  • Create SQL data adapter
  • fill your dataset.

Do not forget to open and close connection. follow this link for more under standing.

Lock screen orientation (Android)

In the Manifest, you can set the screenOrientation to landscape. It would look something like this in the XML:

<activity android:name="MyActivity"
android:screenOrientation="landscape"
android:configChanges="keyboardHidden|orientation|screenSize">
...
</activity>

Where MyActivity is the one you want to stay in landscape.

The android:configChanges=... line prevents onResume(), onPause() from being called when the screen is rotated. Without this line, the rotation will stay as you requested but the calls will still be made.

Note: keyboardHidden and orientation are required for < Android 3.2 (API level 13), and all three options are required 3.2 or above, not just orientation.

How do I generate a random number between two variables that I have stored?

If you have a C++11 compiler you can prepare yourself for the future by using c++'s pseudo random number faculties:

//make sure to include the random number generators and such
#include <random>
//the random device that will seed the generator
std::random_device seeder;
//then make a mersenne twister engine
std::mt19937 engine(seeder());
//then the easy part... the distribution
std::uniform_int_distribution<int> dist(min, max);
//then just generate the integer like this:
int compGuess = dist(engine);

That might be slightly easier to grasp, being you don't have to do anything involving modulos and crap... although it requires more code, it's always nice to know some new C++ stuff...

Hope this helps - Luke

How do I capture SIGINT in Python?

thanks for existing answers, but added signal.getsignal()

import signal

# store default handler of signal.SIGINT
default_handler = signal.getsignal(signal.SIGINT)
catch_count = 0

def handler(signum, frame):
    global default_handler, catch_count
    catch_count += 1
    print ('wait:', catch_count)
    if catch_count > 3:
        # recover handler for signal.SIGINT
        signal.signal(signal.SIGINT, default_handler)
        print('expecting KeyboardInterrupt')

signal.signal(signal.SIGINT, handler)
print('Press Ctrl+c here')

while True:
    pass

Stop Visual Studio from mixing line endings in files

On the File menu, choose Advanced Save Options, you can control it there.

Edit: Here's the documentation, you should have a file open first.

ssh_exchange_identification: Connection closed by remote host under Git bash

I just ran into this today and it was because the server I was trying to connect to was overloaded with processing. So it may be possible that the server is low on memory or CPU starved.

Change hover color on a button with Bootstrap customization

The color for your buttons comes from the btn-x classes (e.g., btn-primary, btn-success), so if you want to manually change the colors by writing your own custom css rules, you'll need to change:

/*This is modifying the btn-primary colors but you could create your own .btn-something class as well*/
.btn-primary {
    color: #fff;
    background-color: #0495c9;
    border-color: #357ebd; /*set the color you want here*/
}
.btn-primary:hover, .btn-primary:focus, .btn-primary:active, .btn-primary.active, .open>.dropdown-toggle.btn-primary {
    color: #fff;
    background-color: #00b3db;
    border-color: #285e8e; /*set the color you want here*/
}

exit application when click button - iOS

You can use exit method to quit an ios app :

exit(0);

You should say same alert message and ask him to quit

Another way is by using [[NSThread mainThread] exit]

However you should not do this way

According to Apple, your app should not terminate on its own. Since the user did not hit the Home button, any return to the Home screen gives the user the impression that your app crashed. This is confusing, non-standard behavior and should be avoided.

Undefined symbols for architecture armv7

There is usually a alias without the version identifier that is linked to the current version, in this case libz.dylib is linked to libz.1.2.5.dylib. Use the base alias instead of the versioned one.

Adjusting HttpWebRequest Connection Timeout in C#

Sorry for tacking on to an old thread, but I think something that was said above may be incorrect/misleading.

From what I can tell .Timeout is NOT the connection time, it is the TOTAL time allowed for the entire life of the HttpWebRequest and response. Proof:

I Set:

.Timeout=5000
.ReadWriteTimeout=32000

The connect and post time for the HttpWebRequest took 26ms

but the subsequent call HttpWebRequest.GetResponse() timed out in 4974ms thus proving that the 5000ms was the time limit for the whole send request/get response set of calls.

I didn't verify if the DNS name resolution was measured as part of the time as this is irrelevant to me since none of this works the way I really need it to work--my intention was to time out quicker when connecting to systems that weren't accepting connections as shown by them failing during the connect phase of the request.

For example: I'm willing to wait 30 seconds on a connection request that has a chance of returning a result, but I only want to burn 10 seconds waiting to send a request to a host that is misbehaving.

Dynamically Add Variable Name Value Pairs to JSON Object

`enter code here`

Create Object from JSON String

_x000D_
_x000D_
var txt = '{"cart":{"sType":1, "produto":[{"pType":1, "pName":"produto original", "valor": 10.00},{"pType":1, "pName":"produto selecionado", "valor": 11.00}]}}';

var obj = JSON.parse(txt);
obj.cart.produto[0]['pName']='nome alterado';
obj.cart.produto[obj.cart.produto.length]={"pType":9, "pName":"produto adicionado", "valor": 19.00};

console.log(obj);

console.log(JSON.stringify(obj));



// compondo objeto JSON
var txt = '{"cart":{"sType":1, "product":[{"pType":1, "pName":"product genuine1", "pValue": 10.00},{"pType":1, "pName":"product genuine2", "pValue": 11.00}]}}';

// criando o objeto
var obj = JSON.parse(txt);

console.log('//log do objeto original');
console.log(obj);

// alterando o valor de uma "key", no caso a pName do produto[0]
obj.cart.product[0]['pName']='nome alterado';

// adicionando uma nova array
obj.cart.product[obj.cart.product.length]={"pType":9, "pName":"produto adicionado", "pValue": 19.00};

console.log('//log do objeto alterado');
console.log(obj);

console.log('//log do objeto alterado em txt');
console.log(JSON.stringify(obj));

// no html
document.getElementById('print').innerText = JSON.stringify(obj);
_x000D_
<html>
<body>

<h2>Manipulando um objeto</h2>
<p id="print"></p>
</body>
</html>
_x000D_
_x000D_
_x000D_

How to display Woocommerce Category image?

From the WooCommerce page:

// WooCommerce – display category image on category archive

add_action( 'woocommerce_archive_description', 'woocommerce_category_image', 2 );
function woocommerce_category_image() {
    if ( is_product_category() ){
      global $wp_query;
      $cat = $wp_query->get_queried_object();
      $thumbnail_id = get_woocommerce_term_meta( $cat->term_id, 'thumbnail_id', true );
      $image = wp_get_attachment_url( $thumbnail_id );
      if ( $image ) {
          echo '<img src="' . $image . '" alt="" />';
      }
  }
}

How to set focus on input field?

Just throwing in some coffee.

app.directive 'ngAltFocus', ->
    restrict: 'A'
    scope: ngAltFocus: '='
    link: (scope, el, attrs) ->
        scope.$watch 'ngAltFocus', (nv) -> el[0].focus() if nv

What is the best regular expression to check if a string is a valid URL?

With regard to eyelidness' answer post that reads "This is based on my reading of the URI specification.": Thanks Eyelidness, yours is the perfect solution I sought, as it is based on the URI spec! Superb work. :)

I had to make two amendments. The first to get the regexp to match IP address URLs correctly in PHP (v5.2.10) with the preg_match() function.

I had to add one more set of parenthesis to the line above "IP Address" around the pipes:

)|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}(?#

Not sure why.

I have also reduced the top level domain minimum length from 3 to 2 letters to support .co.uk and similar.

Final code:

/^(https?|ftp):\/\/(?#                                      protocol
)(([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+(?#         username
)(:([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+)?(?#      password
)@)?(?#                                                     auth requires @
)((([a-z0-9]\.|[a-z0-9][a-z0-9-]*[a-z0-9]\.)*(?#             domain segments AND
)[a-z][a-z0-9-]*[a-z0-9](?#                                 top level domain  OR
)|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}(?#
    )(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])(?#             IP address
))(:\d+)?(?#                                                port
))(((\/+([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)*(?# path
)(\?([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)(?#      query string
)?)?)?(?#                                                   path and query string optional
)(#([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)?(?#      fragment
)$/i

This modified version was not checked against the URI specification so I can't vouch for it's compliance, it was altered to handle URLs on local network environments and two digit TLDs as well as other kinds of Web URL, and to work better in the PHP setup I use.

As PHP code:

define('URL_FORMAT', 
'/^(https?):\/\/'.                                         // protocol
'(([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+'.         // username
'(:([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+)?'.      // password
'@)?(?#'.                                                  // auth requires @
')((([a-z0-9]\.|[a-z0-9][a-z0-9-]*[a-z0-9]\.)*'.                      // domain segments AND
'[a-z][a-z0-9-]*[a-z0-9]'.                                 // top level domain  OR
'|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}'.
'(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])'.                 // IP address
')(:\d+)?'.                                                // port
')(((\/+([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)*'. // path
'(\?([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)'.      // query string
'?)?)?'.                                                   // path and query string optional
'(#([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)?'.      // fragment
'$/i');

Here is a test program in PHP which validates a variety of URLs using the regex:

<?php

define('URL_FORMAT',
'/^(https?):\/\/'.                                         // protocol
'(([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+'.         // username
'(:([a-z0-9$_\.\+!\*\'\(\),;\?&=-]|%[0-9a-f]{2})+)?'.      // password
'@)?(?#'.                                                  // auth requires @
')((([a-z0-9]\.|[a-z0-9][a-z0-9-]*[a-z0-9]\.)*'.                      // domain segments AND
'[a-z][a-z0-9-]*[a-z0-9]'.                                 // top level domain  OR
'|((\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])\.){3}'.
'(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])'.                 // IP address
')(:\d+)?'.                                                // port
')(((\/+([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)*'. // path
'(\?([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)'.      // query string
'?)?)?'.                                                   // path and query string optional
'(#([a-z0-9$_\.\+!\*\'\(\),;:@&=-]|%[0-9a-f]{2})*)?'.      // fragment
'$/i');

/**
 * Verify the syntax of the given URL. 
 * 
 * @access public
 * @param $url The URL to verify.
 * @return boolean
 */
function is_valid_url($url) {
  if (str_starts_with(strtolower($url), 'http://localhost')) {
    return true;
  }
  return preg_match(URL_FORMAT, $url);
}


/**
 * String starts with something
 * 
 * This function will return true only if input string starts with
 * niddle
 * 
 * @param string $string Input string
 * @param string $niddle Needle string
 * @return boolean
 */
function str_starts_with($string, $niddle) {
      return substr($string, 0, strlen($niddle)) == $niddle;
}


/**
 * Test a URL for validity and count results.
 * @param url url
 * @param expected expected result (true or false)
 */

$numtests = 0;
$passed = 0;

function test_url($url, $expected) {
  global $numtests, $passed;
  $numtests++;
  $valid = is_valid_url($url);
  echo "URL Valid?: " . ($valid?"yes":"no") . " for URL: $url. Expected: ".($expected?"yes":"no").". ";
  if($valid == $expected) {
    echo "PASS\n"; $passed++;
  } else {
    echo "FAIL\n";
  }
}

echo "URL Tests:\n\n";

test_url("http://localserver/projects/public/assets/javascript/widgets/UserBoxMenu/widget.css", true);
test_url("http://www.google.com", true);
test_url("http://www.google.co.uk/projects/my%20folder/test.php", true);
test_url("https://myserver.localdomain", true);
test_url("http://192.168.1.120/projects/index.php", true);
test_url("http://192.168.1.1/projects/index.php", true);
test_url("http://projectpier-server.localdomain/projects/public/assets/javascript/widgets/UserBoxMenu/widget.css", true);
test_url("https://2.4.168.19/project-pier?c=test&a=b", true);
test_url("https://localhost/a/b/c/test.php?c=controller&arg1=20&arg2=20", true);
test_url("http://user:password@localhost/a/b/c/test.php?c=controller&arg1=20&arg2=20", true);

echo "\n$passed out of $numtests tests passed.\n\n";

?>

Thanks again to eyelidness for the regex!

jquery onclick change css background image

Use your jquery like this

$('.home').css({'background-image':'url(images/tabs3.png)'});

Switching to a TabBar tab view programmatically?

Try this code in Swift or Objective-C

Swift

self.tabBarController.selectedIndex = 1

Objective-C

[self.tabBarController setSelectedIndex:1];

Program to find largest and second largest number in array

#include<stdio.h>

int main()
{
    int a[10];
    int i,b,c;

    printf("Enter ten values : \n");
    for(i=0; i<10; i++)
    {
        scanf("%d",&a[i]);
    }

    b=a[0];

    for(i=0; i<10; i++)
    {
        if(a[i]>b)
        {
            b=a[i];
        }

        else
        {
            b=b;
        }
    }

    if(b==a[1])
    {
        c=a[2];
    }
    else 
    {
        c=a[1];
    }

    for(i=0; i<10; i++)
    {
        if(a[i]>c && a[i]!=b)
        {
            c=a[i];
        }

        else if (b>c)
        {
            c=c;
        }

    }




    printf("Largest number is %d\nSecond largest number is %d",b,c);

}

How to set java_home on Windows 7?

if you have not restarted your computer after installing jdk just restart your computer.

if you want to make a portable java and set path before using java, just make a batch file i explained below.

if you want to run this batch file when your computer start just put your batch file shortcut in startup folder. In windows 7 startup folder is "C:\Users\user\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup"

make a batch file like this:

set Java_Home=C:\Program Files\Java\jdk1.8.0_11
set PATH=%PATH%;C:\Program Files\Java\jdk1.8.0_11\bin

note: java_home and path are variables. you can make any variable as you wish. for example set amir=good_boy and you can see amir by %amir% or you can see java_home by %java_home%

How to give color to each class in scatter plot in R?

Here is a solution using traditional graphics (and Dirk's data):

> DF <- data.frame(x=1:10, y=rnorm(10)+5, z=sample(letters[1:3], 10, replace=TRUE)) 
> DF
    x        y z
1   1 6.628380 c
2   2 6.403279 b
3   3 6.708716 a
4   4 7.011677 c
5   5 6.363794 a
6   6 5.912945 b
7   7 2.996335 a
8   8 5.242786 c
9   9 4.455582 c
10 10 4.362427 a
> attach(DF); plot(x, y, col=c("red","blue","green")[z]); detach(DF)

This relies on the fact that DF$z is a factor, so when subsetting by it, its values will be treated as integers. So the elements of the color vector will vary with z as follows:

> c("red","blue","green")[DF$z]
 [1] "green" "blue"  "red"   "green" "red"   "blue"  "red"   "green" "green" "red"    

You can add a legend using the legend function:

legend(x="topright", legend = levels(DF$z), col=c("red","blue","green"), pch=1)

Executing a batch script on Windows shutdown

I found this topic while searching for run script for startup and shutdown Windows 10. Those answers above didn't working. For me on windows 10 worked when I put scripts to task scheduler. How to do this: press window key and write Task scheduler, open it, then on the right is Add task... button. Here you can add scripts. PS: I found action for startup and logout user, there is not for shutdown.

Convert List<T> to ObservableCollection<T> in WP7

The answer provided by Zin Min solved my problem with a single line of code. Excellent!

I was having the same issue of converting a generic List to a generic ObservableCollection to use the values from my List to populate a ComboBox that is participating in binding via a factory class for a WPF Window.

_expediteStatuses = new ObservableCollection<ExpediteStatus>(_db.getExpediteStatuses());

Here is the signature for the getExpediteStatuses method:

public List<ExpediteStatus> getExpediteStatuses()

background-image: url("images/plaid.jpg") no-repeat; wont show up

You either use :

background-image: url("images/plaid.jpg");
background-repeat: no-repeat;

... or

background: transparent url("images/plaid.jpg") top left no-repeat;

... but definitively not

background-image: url("images/plaid.jpg") no-repeat;

EDIT : Demo at JSFIDDLE using absolute paths (in case you have troubles referring to your images with relative paths).

jackson deserialization json to java-objects

It looks like you are trying to read an object from JSON that actually describes an array. Java objects are mapped to JSON objects with curly braces {} but your JSON actually starts with square brackets [] designating an array.

What you actually have is a List<product> To describe generic types, due to Java's type erasure, you must use a TypeReference. Your deserialization could read: myProduct = objectMapper.readValue(productJson, new TypeReference<List<product>>() {});

A couple of other notes: your classes should always be PascalCased. Your main method can just be public static void main(String[] args) throws Exception which saves you all the useless catch blocks.

Play sound on button click android

Button button1=(Button)findViewById(R.id.btnB1);
button1.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
MediaPlayer mp1 = MediaPlayer.create(this, R.raw.b1);
mp1.start();
}
});

Try this i think it will work

How can I refresh c# dataGridView after update ?

I know thats an old topic but i suddenly found the best way of doing it and it does not require nullifying the datasource and reassigning it. Just use a BindingList instead of a List.

for example:

//declare your list
private BindingList<myclass> mMyList = new BindingList<myclass>();

//then bind it to your datagrid, i usually do it on the Load event
private void Form1_Load(object sender, EventArgs e)
{
    _dgMyDatagrig.DataSource = mMyList;
}

//start populating your list 
private void addItem(mycclass item)
{
    mMylist.add(item);

//the datagrid will show automatically the new added/updated items, no need to do anything else

}

Get rid of "The value for annotation attribute must be a constant expression" message

This is what a constant expression in Java looks like:

package com.mycompany.mypackage;

public class MyLinks {
  // constant expression
  public static final String GUESTBOOK_URL = "/guestbook";
}

You can use it with annotations as following:

import com.mycompany.mypackage.MyLinks;

@WebServlet(urlPatterns = {MyLinks.GUESTBOOK_URL})
public class GuestbookServlet extends HttpServlet {
  // ...
}

Can I use GDB to debug a running process?

ps -elf doesn't seem to show the PID. I recommend using instead:

ps -ld | grep foo
gdb -p PID

C pointer to array/array of pointers disambiguation

I think we can use the simple rule ..

example int * (*ptr)()[];
start from ptr 

" ptr is a pointer to " go towards right ..its ")" now go left its a "(" come out go right "()" so " to a function which takes no arguments " go left "and returns a pointer " go right "to an array" go left " of integers "

Wait until a process ends

I do the following in my application:

Process process = new Process();
process.StartInfo.FileName = executable;
process.StartInfo.Arguments = arguments;
process.StartInfo.ErrorDialog = true;
process.StartInfo.WindowStyle = ProcessWindowStyle.Minimized;
process.Start();
process.WaitForExit(1000 * 60 * 5);    // Wait up to five minutes.

There are a few extra features in there which you might find useful...

MySQL Job failed to start

In my case, i do:

  1. sudo nano /etc/mysql/my.cnf
  2. search for bind names and IPs
  3. remove the specific, and let only localhost 127.0.0.1 and the hostname

ASP.Net MVC How to pass data from view to controller

You can do it with ViewModels like how you passed data from your controller to view.

Assume you have a viewmodel like this

public class ReportViewModel
{
   public string Name { set;get;}
}

and in your GET Action,

public ActionResult Report()
{
  return View(new ReportViewModel());
}

and your view must be strongly typed to ReportViewModel

@model ReportViewModel
@using(Html.BeginForm())
{
  Report NAme : @Html.TextBoxFor(s=>s.Name)
  <input type="submit" value="Generate report" />
}

and in your HttpPost action method in your controller

[HttpPost]
public ActionResult Report(ReportViewModel model)
{
  //check for model.Name property value now
  //to do : Return something
}

OR Simply, you can do this without the POCO classes (Viewmodels)

@using(Html.BeginForm())
{
   <input type="text" name="reportName" />
   <input type="submit" />
}

and in your HttpPost action, use a parameter with same name as the textbox name.

[HttpPost]
public ActionResult Report(string reportName)
{
  //check for reportName parameter value now
  //to do : Return something
}

EDIT : As per the comment

If you want to post to another controller, you may use this overload of the BeginForm method.

@using(Html.BeginForm("Report","SomeOtherControllerName"))
{
   <input type="text" name="reportName" />
   <input type="submit" />
}

Passing data from action method to view ?

You can use the same view model, simply set the property values in your GET action method

public ActionResult Report()
{
  var vm = new ReportViewModel();
  vm.Name="SuperManReport";
  return View(vm);
}

and in your view

@model ReportViewModel
<h2>@Model.Name</h2>
<p>Can have input field with value set in action method</p>
@using(Html.BeginForm())
{
  @Html.TextBoxFor(s=>s.Name)
  <input type="submit" />
}

Thread Safe C# Singleton Pattern

The Lazy<T> version:

public sealed class Singleton
{
    private static readonly Lazy<Singleton> lazy
        = new Lazy<Singleton>(() => new Singleton());

    public static Singleton Instance
        => lazy.Value;

    private Singleton() { }
}

Requires .NET 4 and C# 6.0 (VS2015) or newer.

How do you run CMD.exe under the Local System Account?

Though I haven't personally tested, I have good reason to believe that the above stated AT COMMAND solution will work for XP, 2000 and Server 2003. Per my and Bryant's testing, we've identified that the same approach does not work with Vista or Windows Server 2008 -- most probably due to added security and the /interactive switch being deprecated.

However, I came across this article which demonstrates the use of PSTools from SysInternals (which was acquired by Microsoft in July, 2006.) I launched the command line via the following and suddenly I was running under the Local Admin Account like magic:

psexec -i -s cmd.exe

PSTools works well. It's a lightweight, well-documented set of tools which provides an appropriate solution to my problem.

Many thanks to those who offered help.

How to upload files to server using JSP/Servlet?

you can upload file using jsp /servlet.

<form action="UploadFileServlet" method="post">
  <input type="text" name="description" />
  <input type="file" name="file" />
  <input type="submit" />
</form>

on the other hand server side. use following code.

     package com.abc..servlet;

import java.io.File;
---------
--------


/**
 * Servlet implementation class UploadFileServlet
 */
public class UploadFileServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public UploadFileServlet() {
        super();
        // TODO Auto-generated constructor stub
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        response.sendRedirect("../jsp/ErrorPage.jsp");
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub

            PrintWriter out = response.getWriter();
            HttpSession httpSession = request.getSession();
            String filePathUpload = (String) httpSession.getAttribute("path")!=null ? httpSession.getAttribute("path").toString() : "" ;

            String path1 =  filePathUpload;
            String filename = null;
            File path = null;
            FileItem item=null;


            boolean isMultipart = ServletFileUpload.isMultipartContent(request);

            if (isMultipart) {
                FileItemFactory factory = new DiskFileItemFactory();
                ServletFileUpload upload = new ServletFileUpload(factory);
                String FieldName = "";
                try {
                    List items = upload.parseRequest(request);
                    Iterator iterator = items.iterator();
                    while (iterator.hasNext()) {
                         item = (FileItem) iterator.next();

                            if (fieldname.equals("description")) {
                                description = item.getString();
                            }
                        }
                        if (!item.isFormField()) {
                            filename = item.getName();
                            path = new File(path1 + File.separator);
                            if (!path.exists()) {
                                boolean status = path.mkdirs();
                            }
                            /* START OF CODE FRO PRIVILEDGE*/

                            File uploadedFile = new File(path + Filename);  // for copy file
                            item.write(uploadedFile);
                            }
                        } else {
                            f1 = item.getName();
                        }

                    } // END OF WHILE 
                    response.sendRedirect("welcome.jsp");
                } catch (FileUploadException e) {
                    e.printStackTrace();
                } catch (Exception e) {
                    e.printStackTrace();
                } 
            }   
    }

}

What is the meaning of polyfills in HTML5?

Here are some high level thoughts and info that might help, aside from the other answers.

Pollyfills are like a compatability patch for specific browsers. Shims are changes to specific arguments. Fallbacks can be used if say a @mediaquery is not compatible with a browser.

It kind of depends on the requirements of what your app/website needs to be compatible with.

You cna check this site out for compatability of specific libraries with specific browsers. https://caniuse.com/

How to restore SQL Server 2014 backup in SQL Server 2008

It is a pretty old post, but I just had to do it today. I just right-clicked database from SQL2014 and selected Export Data option and that helped me to move data to SQL2012.

Using ListView : How to add a header view?

You simply can't use View as a Header of ListView.

Because the view which is being passed in has to be inflated.

Look at my answer at Android ListView addHeaderView() nullPointerException for predefined Views for more info.

EDIT:

Look at this tutorial Android ListView and ListActivity - Tutorial .

EDIT 2: This link is broken Android ListActivity with a header or footer

Calling virtual functions inside constructors

The reason is that C++ objects are constructed like onions, from the inside out. Base classes are constructed before derived classes. So, before a B can be made, an A must be made. When A's constructor is called, it's not a B yet, so the virtual function table still has the entry for A's copy of fn().

How to dynamically create a class?

Runtime Code Generation with JVM and CLR - Peter Sestoft

Work for persons that are really interested in this type of programming.

My tip for You is that if You declare something try to avoid string, so if You have class Field it is better to use class System.Type to store the field type than a string. And for the sake of best solutions instead of creation new classes try to use those that has been created FiledInfo instead of creation new.

Unable to open a file with fopen()

Well, now you know there is a problem, the next step is to figure out what exactly the error is, what happens when you compile and run this?:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    FILE *file;
    file = fopen("TestFile1.txt", "r");
    if (file == NULL) {
      perror("Error");
    } else {
      fclose(file);
    }
}

Interfaces vs. abstract classes

The real question is: whether to use interfaces or base classes. This has been covered before.

In C#, an abstract class (one marked with the keyword "abstract") is simply a class from which you cannot instantiate objects. This serves a different purpose than simply making the distinction between base classes and interfaces.

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)

Add port number (something like 3306) in:

Connection c = DriverManager.getConnection("jdbc:mysql://localhost:urport","root","root");

"Could not find the main class" error when running jar exported by Eclipse

Ok, so I finally got it to work. If I use the JRE 6 instead of 7 everything works great. No idea why, but it works.

Deny access to one specific folder in .htaccess

You can also put this IndexIgnore * at your root .htaccess file to disable file listing of all of your website directories including sub-dir

javascript filter array of objects

The most straightforward and readable approach will be the usage of native javascript filter method.

Native javaScript filter takes a declarative approach in filtering array elements. Since it is a method defined on Array.prototype, it iterates on a provided array and invokes a callback on it. This callback, which acts as our filtering function, takes three parameters:

element — the current item in the array being iterated over

index — the index or location of the current element in the array that is being iterated over

array — the original array that the filter method was applied on Let’s use this filter method in an example. Note that the filter can be applied on any sort of array. In this example, we are going to filter an array of objects based on an object property.

An example of filtering an array of objects based on object properties could look something like this:

// Please do not hate me for bashing on pizza and burgers.
// and FYI, I totally made up the healthMetric param :)
let foods = [
  { type: "pizza", healthMetric: 25 },
  { type: "burger", healthMetric: 10 },
  { type: "salad", healthMetric: 60 },
  { type: "apple", healthMetric: 82 }
];
let isHealthy = food => food.healthMetric >= 50;

const result = foods.filter(isHealthy);

console.log(result.map(food => food.type));
// Result: ['salad', 'apple']

To learn more about filtering arrays in functions and yo build your own filtering, check out this article: https://medium.com/better-programming/build-your-own-filter-e88ba0dcbfae

How do I validate a date string format in python?

The Python dateutil library is designed for this (and more). It will automatically convert this to a datetime object for you and raise a ValueError if it can't.

As an example:

>>> from dateutil.parser import parse
>>> parse("2003-09-25")
datetime.datetime(2003, 9, 25, 0, 0)

This raises a ValueError if the date is not formatted correctly:

>>> parse("2003-09-251")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/jacinda/envs/dod-backend-dev/lib/python2.7/site-packages/dateutil/parser.py", line 720, in parse
    return DEFAULTPARSER.parse(timestr, **kwargs)
  File "/Users/jacinda/envs/dod-backend-dev/lib/python2.7/site-packages/dateutil/parser.py", line 317, in parse
    ret = default.replace(**repl)
ValueError: day is out of range for month

dateutil is also extremely useful if you start needing to parse other formats in the future, as it can handle most known formats intelligently and allows you to modify your specification: dateutil parsing examples.

It also handles timezones if you need that.

Update based on comments: parse also accepts the keyword argument dayfirst which controls whether the day or month is expected to come first if a date is ambiguous. This defaults to False. E.g.

>>> parse('11/12/2001')
>>> datetime.datetime(2001, 11, 12, 0, 0) # Nov 12
>>> parse('11/12/2001', dayfirst=True)
>>> datetime.datetime(2001, 12, 11, 0, 0) # Dec 11

AES Encryption for an NSString on the iPhone

Please use the below mentioned URL to encrypt string using AES excryption with 
key and IV values.

https://github.com/muneebahmad/AESiOSObjC

commons httpclient - Adding query string parameters to GET/POST request

Here is how you would add query string parameters using HttpClient 4.2 and later:

URIBuilder builder = new URIBuilder("http://example.com/");
builder.setParameter("parts", "all").setParameter("action", "finish");

HttpPost post = new HttpPost(builder.build());

The resulting URI would look like:

http://example.com/?parts=all&action=finish

How to check the gradle version in Android Studio?

File->Project Structure->Project pane->"Android plugin version".

Make sure you don't confuse the Gradle version with the Android plugin version. The former is the build system itself, the latter is the plugin to the build system that knows how to build Android projects

Cross-Origin Request Blocked

You need other headers, not only access-control-allow-origin. If your request have the "Access-Control-Allow-Origin" header, you must copy it into the response headers, If doesn't, you must check the "Origin" header and copy it into the response. If your request doesn't have Access-Control-Allow-Origin not Origin headers, you must return "*".

You can read the complete explanation here: http://www.html5rocks.com/en/tutorials/cors/#toc-adding-cors-support-to-the-server

and this is the function I'm using to write cross domain headers:

func writeCrossDomainHeaders(w http.ResponseWriter, req *http.Request) {
    // Cross domain headers
    if acrh, ok := req.Header["Access-Control-Request-Headers"]; ok {
        w.Header().Set("Access-Control-Allow-Headers", acrh[0])
    }
    w.Header().Set("Access-Control-Allow-Credentials", "True")
    if acao, ok := req.Header["Access-Control-Allow-Origin"]; ok {
        w.Header().Set("Access-Control-Allow-Origin", acao[0])
    } else {
        if _, oko := req.Header["Origin"]; oko {
            w.Header().Set("Access-Control-Allow-Origin", req.Header["Origin"][0])
        } else {
            w.Header().Set("Access-Control-Allow-Origin", "*")
        }
    }
    w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE")
    w.Header().Set("Connection", "Close")

}

Find an object in SQL Server (cross-database)

You can achieve this by using the following query:

EXEC sp_msforeachdb 
    'IF EXISTS
    (
        SELECT  1 
        FROM    [?].sys.objects 
        WHERE   name LIKE ''OBJECT_TO_SEARCH''
    )
    SELECT 
        ''?''       AS DB, 
        name        AS Name, 
        type_desc   AS Type 
    FROM [?].sys.objects 
    WHERE name LIKE ''OBJECT_TO_SEARCH'''

Just replace OBJECT_TO_SEARCH with the actual object name you are interested in (or part of it, surrounded with %).

More details here: https://peevsvilen.blog/2019/07/30/search-for-an-object-in-sql-server/

scp (secure copy) to ec2 instance without password

scp -i /home/barkat/Downloads/LamppServer.pem lampp_x64_12.04.tar.gz

this will be very helpful to all of you guys

Create a file if it doesn't exist

Well, first of all, in Python there is no ! operator, that'd be not. But open would not fail silently either - it would throw an exception. And the blocks need to be indented properly - Python uses whitespace to indicate block containment.

Thus we get:

fn = input('Enter file name: ')
try:
    file = open(fn, 'r')
except IOError:
    file = open(fn, 'w')

Pie chart with jQuery

Flot

Limitations: lines, points, filled areas, bars, pie and combinations of these

From an interaction perspective, Flot by far will get you as close as possible to Flash graphing as you can get with jQuery. Whilst the graph output is pretty slick, and great looking, you can also interact with data points. What I mean by this is you can have the ability to hover over a data point and get visual feedback on the value of that point in the graph.

The trunk version of flot supports pie charts.

Flot Zoom capability.

On top of this, you also have the ability to select a chunk of the graph to get data back for a particular “zone”. As a secondary feature to this “zoning”, you can also select an area on a graph and zoom in to see the data points a little more closely. Very cool.


Sparklines

Limitations: Pie, Line, Bar, Combination

Sparklines is my favourite mini graphing tool out there. Really great for dashboard style graphs (think Google Analytics dashboard next time you login). Because they’re so tiny, they can be included in line (as in the example above). Another nice idea which can be used in all graphing plugins is the self-refresh capabilities. Their Mouse-Speed demo shows you the power of live charting at its best.


Query Chart 0.21

Limitations: Area, Line, Bar and combinations of these

jQuery Chart 0.21 isn’t the nicest looking charting plugin out there it has to be said. It’s pretty basic in functionality when it comes to the charts it can handle, however it can be flexible if you can put in some time and effort into it.

Adding values into a chart is relatively simple:

.chartAdd({

    "label"  : "Leads",
    "type"   : "Line",
    "color"  : "#008800",
    "values" : ["100","124","222","44","123","23","99"]
});

jQchart

Limitations: Bar, Line

jQchart is an odd one, they’ve built in animation transistions and drag/drop functionality into the chart, however it’s a little clunky – and seemingly pointless. It does generate nice looking charts if you get the CSS setup right, but there are better out there.


TufteGraph

Limitations: Bar and Stacked Bar

Tuftegraph sells itself as “pretty bar graphs that you would show your mother”. It comes close, Flot is prettier, but Tufte does lend itself to be very lightweight. Although with that comes restrictions – there are few options to choose from, so you get what you’re given. Check it out for a quick win bar chart.

Android Starting Service at Boot Time , How to restart service class after device Reboot?

Pls check JobScheduler for apis above 26

WakeLock was the best option for this but it is deprecated in api level 26 Pls check this link if you consider api levels above 26
https://developer.android.com/reference/android/support/v4/content/WakefulBroadcastReceiver.html#startWakefulService(android.content.Context,%20android.content.Intent)

It says

As of Android O, background check restrictions make this class no longer generally useful. (It is generally not safe to start a service from the receipt of a broadcast, because you don't have any guarantees that your app is in the foreground at this point and thus allowed to do so.) Instead, developers should use android.app.job.JobScheduler to schedule a job, and this does not require that the app hold a wake lock while doing so (the system will take care of holding a wake lock for the job).

so as it says cosider JobScheduler
https://developer.android.com/reference/android/app/job/JobScheduler

if it is to do something than to start and to keep it you can receive the broadcast ACTION_BOOT_COMPLETED

If it isn't about foreground pls check if an Accessibility service could do

another option is to start an activity from broadcast receiver and finish it after starting the service within onCreate() , since newer android versions doesnot allows starting services from receivers

How to have a transparent ImageButton: Android

I was already adding something to the background so , This thing worked for me:

   android:backgroundTint="@android:color/transparent"

(Android Studio 3.4.1)

EDIT: only works on android api level 21 and above. for compatibility, use this instead

   android:background="@android:color/transparent"

How to resolve javax.mail.AuthenticationFailedException issue?

Just wanted to share with you:
I happened to get this error after changing Digital Ocean machine (IP address). Apparently Gmail recognized it as a hacking attack. After following their directions, and approving the new IP address the code is back and running.

call a static method inside a class?

Let's assume this is your class:

class Test
{
    private $baz = 1;

    public function foo() { ... }

    public function bar() 
    {
        printf("baz = %d\n", $this->baz);
    }

    public static function staticMethod() { echo "static method\n"; }
}

From within the foo() method, let's look at the different options:

$this->staticMethod();

So that calls staticMethod() as an instance method, right? It does not. This is because the method is declared as public static the interpreter will call it as a static method, so it will work as expected. It could be argued that doing so makes it less obvious from the code that a static method call is taking place.

$this::staticMethod();

Since PHP 5.3 you can use $var::method() to mean <class-of-$var>::; this is quite convenient, though the above use-case is still quite unconventional. So that brings us to the most common way of calling a static method:

self::staticMethod();

Now, before you start thinking that the :: is the static call operator, let me give you another example:

self::bar();

This will print baz = 1, which means that $this->bar() and self::bar() do exactly the same thing; that's because :: is just a scope resolution operator. It's there to make parent::, self:: and static:: work and give you access to static variables; how a method is called depends on its signature and how the caller was called.

To see all of this in action, see this 3v4l.org output.

Convert string[] to int[] in one line of code using LINQ

EDIT: to convert to array

int[] asIntegers = arr.Select(s => int.Parse(s)).ToArray();

This should do the trick:

var asIntegers = arr.Select(s => int.Parse(s));

How to only get file name with Linux 'find'?

If you are using GNU find

find . -type f -printf "%f\n"

Or you can use a programming language such as Ruby(1.9+)

$ ruby -e 'Dir["**/*"].each{|x| puts File.basename(x)}'

If you fancy a bash (at least 4) solution

shopt -s globstar
for file in **; do echo ${file##*/}; done

Type of expression is ambiguous without more context Swift

This might not be very applicable to others, but my problem was that the changes I made was NOT saved yet! Press CMD + S and save your work before building on top of it.

How to watch for a route change in AngularJS?

This is for the total beginner... like me:

HTML:

  <ul>
    <li>
      <a href="#"> Home </a>
    </li>
    <li>
      <a href="#Info"> Info </a>
    </li>
  </ul>

  <div ng-app="myApp" ng-controller="MainCtrl">
    <div ng-view>

    </div>
  </div>

Angular:

//Create App
var app = angular.module("myApp", ["ngRoute"]);

//Configure routes
app.config(function ($routeProvider) {
    $routeProvider
      .otherwise({ template: "<p>Coming soon</p>" })
      .when("/", {
        template: "<p>Home information</p>"
      })
      .when("/Info", {
        template: "<p>Basic information</p>"
        //templateUrl: "/content/views/Info.html"
      });
});

//Controller
app.controller('MainCtrl', function ($scope, $rootScope, $location) {
  $scope.location = $location.path();
  $rootScope.$on('$routeChangeStart', function () {
    console.log("routeChangeStart");
   //Place code here:....
   });
});

Hope this helps a total beginner like me. Here is the full working sample:

_x000D_
_x000D_
<html>_x000D_
<head>_x000D_
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular.min.js"></script>_x000D_
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular-route.min.js"></script>_x000D_
</head>_x000D_
<body>_x000D_
  <ul>_x000D_
    <li>_x000D_
      <a href="#"> Home </a>_x000D_
    </li>_x000D_
    <li>_x000D_
      <a href="#Info"> Info </a>_x000D_
    </li>_x000D_
  </ul>_x000D_
_x000D_
  <div ng-app="myApp" ng-controller="MainCtrl">_x000D_
    <div ng-view>_x000D_
_x000D_
    </div>_x000D_
  </div>_x000D_
  <script>_x000D_
//Create App_x000D_
var app = angular.module("myApp", ["ngRoute"]);_x000D_
_x000D_
//Configure routes_x000D_
app.config(function ($routeProvider) {_x000D_
    $routeProvider_x000D_
      .otherwise({ template: "<p>Coming soon</p>" })_x000D_
      .when("/", {_x000D_
        template: "<p>Home information</p>"_x000D_
      })_x000D_
      .when("/Info", {_x000D_
        template: "<p>Basic information</p>"_x000D_
        //templateUrl: "/content/views/Info.html"_x000D_
      });_x000D_
});_x000D_
_x000D_
//Controller_x000D_
app.controller('MainCtrl', function ($scope, $rootScope, $location) {_x000D_
  $scope.location = $location.path();_x000D_
  $rootScope.$on('$routeChangeStart', function () {_x000D_
    console.log("routeChangeStart");_x000D_
   //Place code here:...._x000D_
   });_x000D_
});_x000D_
  </script>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

What is Teredo Tunneling Pseudo-Interface?

Unless you have some kind of really weird problem, keep it. The number of IPv6 sites is very small, but there are some and it will let you get to them even if you're at an IPv4 only location.

If it is causing you a problem, it's best to fix it. I've seen a number of people recommending removing it to solve problems. However, they're not actually solving the root cause of the issue. In all the cases I've seen, removing Teredo just happens to cause a side-effect that fixes their problem... :)

Assigning variables with dynamic names in Java

What you need is named array. I wanted to write the following code:

int[] n = new int[4];

for(int i=1;i<4;i++)
{
    n[i] = 5;
}

How to see the changes between two commits without commits in-between?

Asking for the difference /between/ two commits without including the commits in-between makes little sense. Commits are just snapshots of the contents of the repository; asking for the difference between two necessarily includes them. So the question then is, what are you really looking for?

As William suggested, cherry-picking can give you the delta of a single commit rebased on top of another. That is:

$ git checkout 012345
$ git cherry-pick -n abcdef
$ git diff --cached

This takes commit 'abcdef', compares it to its immediate ancestor, then applies that difference on top of '012345'. This new difference is then shown - the only change is the context comes from '012345' rather than 'abcdef's immediate ancestor. Of course, you may get conflicts and etc, so it's not a very useful process in most cases.

If you're just interested in abcdef itself, you can do:

$ git log -u -1 abcdef

This compares abcdef to its immediate ancestor, alone, and is usually what you want.

And of course

$ git diff 012345..abcdef

gives you all differences between those two commits.

It would help to get a better idea of what you're trying to achieve - as I mentioned, asking for the difference between two commits without what's in between doesn't actually make sense.

How do I get the logfile from an Android device?

Logcollector is a good option but you need to install it first.

When I want to get the logfile to send by mail, I usually do the following:

ReactJS - Call One Component Method From Another Component

You can do something like this

import React from 'react';

class Header extends React.Component {

constructor() {
    super();
}

checkClick(e, notyId) {
    alert(notyId);
}

render() {
    return (
        <PopupOver func ={this.checkClick } />
    )
}
};

class PopupOver extends React.Component {

constructor(props) {
    super(props);
    this.props.func(this, 1234);
}

render() {
    return (
        <div className="displayinline col-md-12 ">
            Hello
        </div>
    );
}
}

export default Header;

Using statics

var MyComponent = React.createClass({
 statics: {
 customMethod: function(foo) {
  return foo === 'bar';
  }
 },
   render: function() {
 }
});

MyComponent.customMethod('bar');  // true

Is there a way to cast float as a decimal without rounding and preserving its precision?

cast (field1 as decimal(53,8)
) field 1

The default is: decimal(18,0)

How to ignore files/directories in TFS for avoiding them to go to central source repository?

I found the perfect way to Ignore files in TFS like SVN does.
First of all, select the file that you want to ignore (e.g. the Web.config).
Now go to the menu tab and select:

File Source control > Advanced > Exclude web.config from source control

... and boom; your file is permanently excluded from source control.

How do I list all the columns in a table?

For MS SQL Server:

select * from information_schema.columns where table_name = 'tableName'

Error in installation a R package

After using the wrong quotation mark characters in install.packages(), correcting the quote marks yielded the "cannot remove prior installation" error. Closing and restarting R worked.

How do you implement a class in C?

C Interfaces and Implementations: Techniques for Creating Reusable Software, David R. Hanson

http://www.informit.com/store/product.aspx?isbn=0201498413

This book does an excellent job of covering your question. It's in the Addison Wesley Professional Computing series.

The basic paradigm is something like this:

/* for data structure foo */

FOO *myfoo;
myfoo = foo_create(...);
foo_something(myfoo, ...);
myfoo = foo_append(myfoo, ...);
foo_delete(myfoo);

Swift Alamofire: How to get the HTTP response status code

Or use pattern matching

if let error = response.result.error as? AFError {
   if case .responseValidationFailed(.unacceptableStatusCode(let code)) = error {
       print(code)
   }
}

vi/vim editor, copy a block (not usual action)

You can do it as you do in vi, for example to yank lines from 3020 to the end, execute this command (write the block to a file):

:3020,$ w /tmp/yank

And to write this block in another line/file, go to the desired position and execute next command (insert file written before):

:r /tmp/yank

(Reminder: don't forget to remove file: /tmp/yank)